A HALF DOZEN little puffs of dust, that were running ostriches, fled before the slow-moving caravan. Heat rose from the hot desert sands like blasts from a fiery furnace. The only sounds were the rustle of the camels’ feet and the dull, dead shifting of the sand as it crept slowly westward before the hot, dry wind.

As the sun plunged toward the sea of sand the breathless wind became a half gale. It whipped sand eddies into the cracked lips and chapped faces of the two men who led that long, thin line of pack camels. The Bedouins astride the baggage and riding camels drew their head cloths tighter across their noses, pulled the brow folds forward like visors, leaving only a slit from which their granular, burning eyes peered.

Their cartridge belts held their brightly colored cloaks tight at the waist to keep out the swirling sands. They wore their long rifles slung across their shoulders, and from their belts protruded the hilts of their ever-present daggers.

There was only the shifting of the sands, the padding of the camels' feet, the creaking saddles, the tinkle of bells to disturb the peace and quiet of dusk. No living thing moved across the desert wastes to disturb the solitude of that lone caravan.

Yet; something that was almost tangible, something like a tangible wave of terror crept the length of that long, thin line of camels, as the blood-red sun disappeared and the desert night plummeted down upon the caravan. The camels, seeming to sense that fear, nervously tossed their heads from left to right and bawled their uneasiness.

The two men in the lead glanced furtively at one another and licked their shriveled lips with tongues that were dry and swollen. They shifted in their saddles and glanced back at the rest of the caravan as the desert night swallowed them up. The long, thin line became a sinuous snake, the head or tail of which could not be seen from the center because of the dungeon blackness.

In an hour the wind died and the sky became calm and black and full of stars. Ahead they could see Sand hills coated with tamarisk in the glow of the moon.

Beyond that first rim of sand hills the camels' feet padded on a floor of mud that was baked hard and was as flat as a lake. It extended to the first low hills of limestone that became great peaks against the sky in the distance.

"We shall find water within the Bab es Siq," one of the leaders said to his companion, in Arabic. His words came in the dull, rasping voice of a man who is parched. His companion acknowledged the words with a guttural grunt.

He was thinking of that long, desperate trek across the burning sands of the Great Nefud that lay behind them. He was thinking that now after the finger of Eternity had flicked them a half hundred times they should be safe. He was thinking of the riches they would divide once when they had marketed their cargo, if they got it safely home. His cracked lips twisted into a snarl at that word. If. Nothing, he told himself, could stop them now. He touched his hand to the bag of pearls that had come from the Persian Gulf. Sweet visions of his future life formed in his mind. His snarl became a smile.

In two hours they came to Es Siq, a cleft in the red sandstone hills. A Bedouin carried a blazing torch to lead the line of baggage and pack camels. Stupendous walls, in some places only twenty feet apart, and towering so high that in daytime the caravan would have looked like a line of ants from the top, hemmed them in on both sides.

Even the camels ceased their grumbling and became quiet, afraid to flaunt their smallness in this gigantic work of Nature. Now and again, a single star twinkled in the dungeon of blackness overhead. The sweet odor of oleander was heavy in the air. It floated down the gorge of the Wadi Musa like the scent of ancient caravans bearing perfumes, frankincense, and myrrh.

They crawled along the bed of the Wadi Musa with weary, aching bodies. The half-conscious riders brought their camels' heads up with a jerk as they stumbled. The only thing that kept the riders in their saddles was the thought 'that soon they would feel cool, delicious water trickling down their throats. Then they could sleep the sleep of the weary. A few more days would bring an end to their long journey. There would be pay and a bonus, and the soft laughter of women, and that nameless fear would be behind them.

Because they were half-asleep, they were unprepared when that first blast of gun fire crashed down the gorge and reverberated against the high sandstone walls.

Es Siq became a place of flao1ing guns, screaming animals and mad fanatics. Those two in the lead went off their camels with the first fusillade, their heads, literally, ripped from their bodies by a storm of machine-gun bullets.

The Bedouin riders, astride the camels, screamed for mercy as they were shot out of their saddles by the cloaked and turbaned madmen who poured out of the crannies and fissures that lined Es Siq.

The man who led them was tall and slender, with deep-set eyes that burned like twin fires. A black beard covered half his colorless face. His long, white silk robe streamed out behind him as he shouted orders. His brown head cloth, bound, with a scarlet-and-gold cord, stood out as torches blazed in the gorge. His face became as mad as the faces of his men as he slashed the clothing off the two leaders of the caravan with his dagger and searched it for treasure.

The thing that took place in Es Siq that night was horrible to behold. As each man fell from his camel an Arab dagger was slashed across his throat until his blood gushed out and his life departed. Their rifles and daggers and all their belongings were stripped from them.

A solid line of men stood at each end of the caravan, a line of grim, bearded men dressed in the robes of the nomad Bedouin. They were so placed to see that not one man of that caravan escaped to tell the tale.

When the pack and baggage camels were hobbled and quieted, Serj el Said, the leader of the bandits, shouted a command. Two lean, bronzed Europeans, wearing sun helmets, slacks, and automatics strapped around their waists, leaped to his side.

"Kill that dog who is trying to cut the ropes of the first pack!" he directed them.

One of them brought his automatic up. It barked three times. The Bedouin's body jerked as the bullets tore into him. His scream rose above the babble of his mates, then died as he plunged to the ground. The other Bedouins watched his body twitch convulsively. It was their custom that with victory came the right to plunder. They had become a pack of screaming, clawing zealots. Their hands sped toward the daggers in their belts.

Serj el Said watched them with an expression of contempt on his colorless face. Then he lashed them with words in Arabic.

"Are you men or dogs?" he asked them. "Do you snarl and claw and spit in your filthy greed while there was work yet to be done? We must lash those carrion to their camels and take them to the gorge of the Wadi es Siyagh. They must not be found here. Only Douglas, the infidel, will be found here by the British."

The Bedouins, grumbling, began tying the dead camel riders to the backs of their camels. Serj el Said spoke to his two European lieutenants in precise English.

"Bring Douglas," he said, sneering. "He will be what you call a red herring drawn across the trail of our countrymen."

They disappeared into one of the fissures that lined the mighty gorge. When they came into view again they were half-leading and half dragging a man between them.

The man's face and head were bruised and discolored. His clothes were in tatters. Anyone could see that each step cost him agony beyond description. But his eyes were bright and unafraid. He carried his head high as he tried to laugh at the men on either side of him. There was an air of youth and courage and clean perfection about him.

"If I must die," he said, "I’m glad I learned what dirty rats framed me. No lower form of life ever existed."

"Shut up!" one of the men snarled. He was a huge bulk of a man with a thatch of sandy hair, and a scar that ran from temple-to chin. His voice was a deep roar that became louder and louder as he spoke. His ham-like hands pressed cruelly into the shoulder of Douglas.

"MacTavish and Sneed," Douglas sneered. " A disgrace to-their king and country. Two of the foulest traitors that ever wore the uniform."

Sneed's pig-like eyes narrowed to mere slits as he banged the back of his hand across Douglas' mouth.

"Shut up, you swine!" he grated. "How would you like to have me turn you over to those mad Bedouins over there? They'd teach you how to be still by cutting out your tongue and staking you down in the desert sand."

They flung the white-faced Douglas against a wall of the gorge as Serj el Said came over beside them. His dark eyes gleamed malevolently as he gazed at Douglas.

"You'll be one less Englishman for me to cope with," he said. He turned to MacTavish and Sneed. "Well," he asked them, "why don't you kill him?"

A smile flitted across Douglas' face as he saw the momentary hesitation of the two Englishmen. He knew it would do him no good to plead for mercy. Nor would he have pleaded if he knew it would save his life. He was cast from a different mold than those other two.

It gave him no 'little satisfaction to see that they hesitated to murder a man who had been their fellow officer. He watched them with a smile on his lips and in his eyes. He was determined to die as he had lived, with his head up, afraid to look no man in the eye.

As MacTavish and Sneed drew their guns from their holsters, he spoke:

" A fitting job for two brave and noble officers," he said, almost lightly. "You should receive a citation from your greasy leader. You're not fit to associate with vermin. You

His body jerked and spun half around as MacTavish fired two bullets into his heart.

"That'll stop his mealy mouth!" MacTavish roared.

It did.

MacTavish rolled him over with his boot. Blood welled out of the two wounds and spread in a pool around him, His face was serene, as strong and determined in death as it had been in life.

WING COMMANDER Norton Kestrel, M. C., D. F. C., raised his eyes from the book he was trying to read and shook his head angrily. He was aware that he had read the same paragraph at least a dozen times and did not know yet what he had read. He threw the book down and glanced around his comfortable quarters on the Royal Air Force field at Ma'an in Trans-Jordan.

His mind flitted back to the disturbing reports he had received from British intelligence units in his area. Those reports might have something to do with the eight I single-seater fighters that had been stolen from under his nose. And for the sabotage that had occurred.

He got to his feet and began to pace back and forth across the room, his rugged chin out-thrust, his teeth clenched. He ran a hand through his fast-graying hair and across his lined cheek.

He had turned all of Trans-Jordan upside down trying to locate those eight ships. They had all disappeared at one time while he had been in Alexandria, Egypt, receiving secret instructions. One night the eight ships had been in their hangars. The next morning they had been gone. Other ships had been damaged. British and native intelligence men had worked on the case without results.

What he asked himself, was the connection between the theft of British air force planes and the restlessness of the natives? Who had been able to make those planes vanish like a magician slipping things up his sleeve?

The only result of his investigations had been the cashiering of young James Douglas, a flight officer under his command.

Kestrel's heart ached as he remembered the expression of anguish on Douglas' face when his wings had been ripped from his tunic. He would not have believed Douglas guilty of theft if the evidence had not been annihilating. But he had not been able to justify Douglas' connection with the theft of the eight fighters.

Beads of perspiration came out on Kestrel's head as he sat down and began to remove his boots. He could feel that some insidious thing was hemming him in, fastening invisible tentacles around his throat so that he could feel them in his sleep, bringing him to consciousness with his body dripping, his face twisted in horror.

He began to realize that when he found out what this insidious thing was it would be too late. When the screws began to turn he would be helpless.

He pulled off one boot and started on the other one when he heard staggering footsteps scuffing in the hallway. He started toward the door, then stopped. It would be one of his men, drunk, he thought. He didn't want any more trouble to think about. He sat down again as something thumped against his door and he heard a scraping sound as it slipped to the floor.

The thing that lay there, when he opened the door, wore the usual mantle and head cloth of the native. But the clothes of this man were saturated with blood. The man's face was twisted in agony. ,

Kestrel shouted for help and dropped to his knees. , When he opened the man's mantle he found that his chest was horribly shot away. He tried to stanch the flow of blood as the man opened his eyes. The man’s lips moved slowly, but no sound came from them. He was trying desperately to speak before he died. Kestrel lifted his head and held his ear close to the man’s lips. The man spoke to him in Arabic; his swarthy face became convulsed with pain. Blood gurgled in his throat and spurted out of his mouth.

"Es Siq," he whispered, in Arabic. "Caravan-murder!"

That was all. His body went limp in Kestrel's arms as life left him.

"Get him to a doctor, quick!" Kestrel barked to the men who came running. "He is one of our native intelligence men."

He was cursing as he got his adjutant on the telephone. Why couldn't the man have lived to tell his story?

"Order McCoy to get a fully equipped and armed camel corps ready for departure immediately," he snapped. "Tell him to use his fastest he-camels and take a medical unit along-and to saddle a camel for me."

THE Imperial Camel Corps rose from their knees and bellowed as Major Duff McCoy, astride a tall, large-boned beast, roared, "Walk-march!" to his men.

They thundered out of Ma'an into a bitter north wind. The slopes ahead were silent and black. There was something searching and almost dangerous in that steady desert wind that blew in their faces.

The tough, lean desert Bedouins astride the camels rode them as though they had been born on their backs. The camels were trained to walk Arab fashion, with that bent-kneed gait that made their stride a little longer and a little quicker than the normal. They were finely bred beasts, but bad-tempered and half-wild. With noses high and wind-stirred hair they jigged along at an uneasy dance that took them over the night sands swiftly.

"Was the Arab who gave you the warning one of our men?" McCoy shouted at Kestrel above the wail of the wind.

"Yes," Kestrel answered. "He had been working among the natives, trying to find out something about the disappearance of those half dozen caravans that have vanished around Petra. He must have attached himself to this caravan to see what he could find out. He could only say four words before he died"

"He'll never tell what he found out," McCoy said.

It was dawn when the camel corps entered Es Siq, that-cleft in the red limestone hills that was a trail of the ancient world. Centuries ago the Romans tapped the wealth of Petra by building two roads to it. When Rome fell, Petra was abandoned except for a few desert tribesmen who lived miserably in its tombs and caves.

A poet sang of ancient Petra a hundred years ago: "The rose-red city, half as old as time." Its first written history is to be found in the Bible when it was the home of the Horites, cave dwellers whose progenitor was Hori, the grandson of Seir.

For centuries Petra was the rich crossroads of the world. The Arabian peninsula was a network of caravan routes. The products of Africa, Arabia, and India were taken through Petra and re-routed to the valley of the Nile, Palestine, Phoenicia, and the Euphrates-Tigris valley.

On this morning the descendants of those same desert tribesmen, who occupied the tombs and caves of Es Siq a thousand years ago, gazed down on the Imperial Camel Corps as it made its way between the massive ramparts, of red and purple and yellow.

Traces of the arch and gate, that once made Petra impregnable, faded away into mammoth clumps of oleander blossoms. The unbroken walls were like gigantic skyscrapers along two sides of a street. Caverns high up on the sides were like huge windows. Dark stains that were sometimes red and sometimes purple jetted down the sides.

The Imperial Camel Corps was silent, as had been that caravan the night before, as it gaped at the wonders of Es Siq.

McCoy and Kestrel were taut and tense as they watched for some sign of the slaughter of the night before. For a half mile nothing came to their gaze except the ominous walls of the cleft and the pebbled floor.

As they came abruptly around a corner they saw a thing huddled on the limestone floor. It was as red as the sandstone rocks above it. A half dozen huge and ugly vultures scurried away and winged into the air.

Kestrel's face was white and was trembling as he spoke to McCoy a few moments later.

"It looks as though our court-martial was right," he said. "Douglas must have been a thief and a murderer, too, if he was mixed up in this thing. I've always thought until now that we might have been wrong."

"This settles that," McCoy replied. "But where is the caravan? Where are the bodies of the men who were murdered? Where are the camels?"

"We'll leave the majority of the men here and take a half dozen on into Petra, with a machine gun," Kestrel said grimly. "This thing of caravans disappearing completely is giving me the creeps, McCoy. I'll dispatch two I messengers back to Ma'an with orders for three of our ships to search from the air in this vicinity. They'll probably find nothing. This thing is tied up to the theft of our planes and the sabotage."

Kestrel, McCoy, and six native riders kept on up the cleft until the temple, El--Khazna, burst upon them unexpectedly. The sheer beauty and mystery of the place kept them silent. They watched the changing colors of the ancient temple as it became red under the sun.

Something within them stirred as they tried to grasp the significance of the centuries that had raced by since unknown men had cameoed out this temple to an unknown deity. What could the mute figures on its face tell of the past and the present, and of the ancient city of Petra that was lost to man for a thousand years?

They passed the theater that had been constructed in the days of the Romans, and the ruins on the temple, Qasr el Bint, that was once the castle of Pharaoh's daughter.

They were silent, as men will be when they are with their thoughts, as they entered the crumpled ruins of the ancient city. At first sight it looked as though they were within a blind pocket with two ranges of sandstone mountains on the right and the left, and ancient walls to the north and south.

But nature had cracked an entrance to the east through Es Siq and to the west by the Wadi es Siyagh.

They searched the amphitheater and tombs and temples of the city, studied the great high place of sacrifice on the Zibb Atuf through glasses. They stood at the base of the highest mountain in Petra, Umm el Biyara, and tried to find the ancient stairway that made the flat-topped fortress accessible to man.

They turned their glasses on the Holy of Holies, the top of Jebel Harun-the Moslem shrine of Aaron. They knew that within the mosque was the only Dushara still in use, except. the black stone of the Kaaba in Mecca. They knew that the site is so sacred that no non-Moslem is allowed to enter or even approach its holy precincts, so they turned their glasses away.

"It seems incredible that we can find only tracks," Kestrel said. "They would have to stop and rest the camels unless they killed them and took the cargo on fresh camels. What did they do with the riders they killed?"

"Probably threw them into the gorges of the Wadi Musa," McCoy said. "But they couldn't get out of here with camels unless they went out through Es Siq. '"The Wadi es Siyagh is impassable to caravans now."

"You think they're still in here?"

"I don't know" McCoy answered. "I don't know where they could be unless they are up there on Jebel Harun, the Moslem shrine. And they couldn't get camels up there."

"Nor would they dare," Kestrel said. "An army of a thousand hostile Bedouins would come out of the hills if they attempted to defile the sacred image of Dushara." "That's true," McCoy said. "I think our best bet is to comb the place from the air. You may have a report from the three planes you ordered out."

"We'll go back to Ma'an and leave a small garrison in Es Siq," Kestrel said. "We're going to have trouble, McCoy. Hell is going to pop around here. I want to get into the rooms of young Douglas in Ma'an and see what I can find. There may be a clue there."

COMMANDER KESTREL puckered his brow as he read the letter he had found in James Douglas' room. He had gone through Douglas' effects thoroughly, without finding a single thing that gave any clue to his death, until he found that letter.

DEAR BILL:

I don't know whether you will receive this before you leave China. I got your letter yesterday, and I can't tell you how appreciative I am.

But first let me wish you luck in China. I hope you get an order from the Nanking government for a couple of hundred planes. Good luck to you on that score!

As I told you in my last letter there are queer things going on here. The natives are restless and our Intelligence can't seem to get to the base of the thing. Eight of our fighters were stolen off the Royal Air Force field" Sabotage has been committed again and again. The whole thing remains a mystery. Then I was framed and stripped of my pips and wings and drummed off the field in disgrace.

You say in your letter that you will pick me up on your way back from China. You speak of flying from Nanking to Barnes Field, New York, as though you were going for an evening stroll!

Just one thing: I must clear my name before I leave here. I am going to do that, or die trying. I know you will understand how I feel about this. Our wing commander-Kestrel-is beside himself. There is treachery and danger, in the very air. You can almost see it. I know more about it than I can tell you in a letter. When you arrive here I will tell you what I know and, perhaps, you will help me unravel the thing.

I had always wanted to come to Arabia-"the land of mystery and romance." The mystery is still left, but not the romance.

I can't tell you how this thing is burning inside me, Bill.

I –---

There was a lump in Kestrel's throat as he came to the point where Douglas had stopped writing. He could picture young Douglas writing it, ready to pour out his soul to relieve his feelings. He wondered if a man could write a letter like that and still be guilty. He doubted it. Yet, stolen articles had been found in Douglas' rooms. He wondered for the first time if, as Douglas had claimed, he had been framed.

What, he asked himself, did Douglas know that he, Kestrel, didn't know? Was that the reason his dead body had been found in Es Siq?

He shook his head, angrily, as his thoughts' jumped from Douglas to Bill Barnes. Barnes was coming to Ma’an!

The thought struck him like a bludgeon. Perhaps, because of Douglas, Barnes would help him untangle the threads that were binding him tighter and tighter. He stuck the letter in his pocket and started for his office. He determined to call a conference of his flight officers immediately.

KESTREL frowned as he gazed at the faces of the men before him. McCoy of the camels; McCardell of the medical; Kestrel’s adjutant, Creighton; Group Commanders Braddock and Hector; six squadron commanders and a bevy of flight officers. Kestrel's eyes stopped their wandering momentarily as they fell on the huge bulk of a man with a thatch of sandy hair and a scar that ran from temple to chin, then wandered on to the pink-faced man with pig-like eyes who sat beside him. The curious intentness of their faces startled him for a moment and he tried to remember their names. They flashed through his mind -- MacTavish and Sneed.

He leaned forward and raised a hand for silence.

"Gentlemen," he said, "you no doubt have an idea as to why I have called this conference. But let me impress upon you that you have no inkling of the seriousness of the situation confronting us. "I think it is best if I am frank with you. I was in receipt today of a communication from Sir Ronald, high commissioner of Trans-Jordan. He points out to me in no uncertain words that the Arabs in Palestine, Trans-Jordan, and Arabia are preparing to revolt.

"Some faction has aroused them. Trans-Jordan seems to be the center of their activities.

"Sir Ronald goes on to say that he knows we must constantly keep an eye on developments in the Mediterranean and the Red Sea and that we are in no position to withstand an Arab revolt with conditions as they are all over the world. We must nip the thing in the bud."

Kestrel stopped speaking, cleared his throat and ran his anxious eyes over the men before him.

"Anyway, that puts it up to us. I've known that something was brewing from the reports I have had from our intelligence men scattered over this area. Now I know why we had eight planes stolen from under our noses, and why others have been damaged. Also, I know why a half dozen caravans have mysteriously disappeared within the past few months. The goods those caravans " Carried can be traded for guns and bullets. The sacking, of those caravans helps build up the illusion in the minds of the fanatical Bedouins that all the desert and anything that moves on it belongs to them."

Kestrel raised one hand and shook a finger at his men. His face was suffused with color and his eyes were spitting fire.

"Gentlemen," he went on, his voice rising, "whoever secured those eight planes from our field could not have done so without help from inside the field. Some place among us there are traitors. We must find them. I thought we had found the beginning when we convicted James Douglas of being a common thief and drummed him off the field.

"Now I am not so sure. You all know we found his body in Es Siq this morning. The two bullets we dug out of him came from a British army automatic!

"We have been able to find no trace of the caravan that was waylaid and confiscated in whole last night. But we do know that such a caravan went into Es Siq last night. I have checked with Jerusalem and found that the caravan carried riches beyond estimate, pearls and l black coral from the Persian Gulf. That caravan went into Petra, but never came out just as others have disappeared in the same mysterious manner.

"The same organization that looted our field looted those caravans, with help from some one inside our own lines. Douglas was killed with a British bullet. He was left there for a reason. Perhaps it was as a warning to us. That we will find out in due time.

"When we went through Douglas' effects to-day I found a letter he had been writing to Bill Barnes, the world-famous American. He had evidently written to Barnes telling him of his degradation with our forces. Barnes listened to his plea and offered him a place with his organization. That was probably due to the influence of Hassfurther, Barnes' chief of staff. He flew with Douglas' older brother in a British squadron during the World War.

"Barnes is on his way here now. He is coming to pick up Douglas on his way home from a business transaction in China."

"Sir," Group Commander Hector said, "what has Barnes to do with us?"

"I'm coming to that," Kestrel said. "You know our situation here. You know that any overt act on our part will have the Arabs on us, slitting our throats. We must keep an eye on the situation at Alexandria and Port Said constantly: --"

"It is possible that we may interest Barnes in our plight because of his interest in young Douglas. He does not know Douglas is dead. From what I have heard of him he is a man of action and one who gets results. He may be able to track down the source of the theft of our planes and the murder and disappearance of those half dozen caravans. We must be ready to cooperate with him in every way possible.

"And, gentlemen, we must track down the traitors that are within our midst. Check all of your men. Keep an eye on them. No one is above suspicion. I do not wish to have this wing of the Royal Air Force a disgrace to the finest air corps in the world!"

"When," Group Commander Hector asked, "will Barnes arrive here?"

.'To-night sometime," Kestrel replied. .'l have been in touch with the airport at Bagdad, after checking back on his route as far as Calcutta. He will follow the regular air route over the Hamad Desert."

.'He is alone?" Hector asked. .'He is flying his Silver Lancer," Kestrel said. "Hassfurther, Gleason, and Sanders are with him, flying the famous Snorters."

GROUP COMMANDER HECTOR threw off his belt and tunic and sat down in an easy-chair in .his quarters. He was a big man with iron-gray hair and a round, inscrutable face. He sat, now, as immobile as a stone Buddha, staring straight ahead of him;

He called, "Come in," as a low knock sounded on his door. He didn't speak to MacTavish and Sneed as they came in the door. Instead, he stared at them as he had been staring straight ahead a few minutes before. Even the huge MacTavish fidgeted under his gaze.

Finally, Hector spoke. "You carried out my orders?" he asked.

"Yes, sir," Sneed answered. "Our men are on the way. But there is one thing I wanted to mention to you, sir. The men are frightened."

"Frightened!" Hector roared. "They'll be more than frightened if they don't carry out your orders."

"They're nervous about Kestrel," MacTavish said gruffly. "They know what the British government can do to a man."

"You're a fine pair," Hector sneered. He pointed a long finger at them. "Drum into their heads that they don't have to be nervous about the British unless they go yellow and talk. Get it through their heads they're in this thing now. There isn't any turning back. I'd drive it into their heads if it wasn't dangerous for me to be seen talking to them.

"Make 'em understand that they have everything to gain. None of us is in this for glory. With Serj el Said on the throne of Arabia and Trans-Jordan, the British won’t be able to touch us. And he'll be there. The British haven't time to stop and fight an Arab revolt with half the world ready to go to war. We're the ones on the inside. We'll get the cream. Make your men understand that."

"Are you sure you can trust Serj el Said?" MacTavish asked. "When I - when Douglas was shot last night Serj el Said said, "You'll be one less Englishman for me to cope with.' "

So you're getting nervous, too, eh?" Hector sneered. Again he pointed his finger. "Listen! I have Serj el Said tied to me the same way I have you tied. I could put both of you in a military prison for the rest of your lives. I could do the same with him. You, in turn, have the same hold on your men if you carried out my instructions as I told you to carry them out.

"Don't forget that I have you just where I want you. And don't think I won't turn on the pressure if I think it necessary."

"What about yourself?" MacTavish asked. "Do you think you can get out clean if some, one talks?"

Hector came out of his chair like a thing on springs. His face was purple as he roared at MacTavish.

"Say 'Sir' when 'you speak to me, you swine!" he shouted.

"Sh-h!" Sneed said, stepping between the two men. "We'll get no place shouting at one another. I think it's time we got under way. Our men have already gone. We'll report to Serj el Said at Petra."

His right elbow prodded MacTavish in the side as he finished speaking. MacTavish tried to twist his ugly face into a smile, and half succeeded.

"Sneed is right, sir," he said. "You can depend on my loyalty, sir. All three of us are tense. You know things are going to crack wide open quite soon. It's getting inside me."

"I understand, MacTavish," Hector grunted. "But keep in mind that there must always be one leader, and to remain leader he must crush opposition without mercy.

"I'm depending on you two to keep your men lined up. When we're ready to strike, things will have to work with the precision of a machine. There can't be any slips. I'm tying up the loose ends now so that there won't be any Slips. A lot depends on your success tonight. You mustn't fail. You'll have the advantage of a surprise attack and superior numbers.

"Carry on with your assignment!"

"MacTavish and Sneed saluted smartly and took their leave. Hector threw his J big hulk into the same easy-chair and again stared straight ahead of him, as immobile as a stone Buddha.

AS the two dark forms of MacTavish and Sneed slunk out of the officers' quarters on the Royal Air Force field, Wing Commander Norton Kestrel sat in his own quarters, staring at his adjutant as though he could not believe what the man had just told him. .

His sunken eyes and lined cheeks gave mute evidence of the fact that he had not had sleep for over thirty-six hours. His twitching face was pale beneath its coat of tan.

"You're sure of this, Creighton?" Kestrel whispered.

"Positive," Creighton answered. "Two of our Beersheba spies just made a report to me. They are thoroughly reliable. The Bedouins are gathering in tribes."

"But what Moslem would dare to mutilate the Dushara?" Kestrel asked, his voice stunned. "If the natives believe we did it, the lives of non-Moslems will not be worth a farthing. If we start using an air patrol above the mosque on Jebel Harun it will only add to the natives' conviction that we have c tried to enter the Holy of Holies."

"I'll get word through to Amman, Jerusalem, and Mecca," the adjutant said. "The natives will strike when their leader tells them he is ready."

"We will have to evacuate all women and children and double all guards," Kestrel said, pulling at his haggard face. "I'll issue general orders, immediately. Then I must have some sleep. Barnes will be here sometime before morning. I wish to see him the minute he arrives."

THE PROPS of the three Snorters and the silver bullet that was the Lancer were ticking over slowly as Bill Barnes came out of the administration, building of the airport at Bagdad. The goggled, white-helmeted heads of "Shorty" Hassfurther, Bill's chief of staff, "Red" Gleason, and young "Sandy" Sanders, the youngest of Bill's little squadron of aces, jutted above the rim of their yellow-and-black-and-red amphibians.

They were waiting, impatiently, for Bill to signal the dispatch tower. Luggage, ammunition, emergency equipment in the tails, and fuel had been carefully checked.

Shorty Hassfurther, that blue-eyed broad-faced veteran of a thousand battles in the air, wanted to be on his way to the Royal Air Force field at Ma'an. He wanted to see and talk to James Douglas, the brother of an old War-time pal. He had seen young James a half dozen times in England since his brother r had been killed. And once, young Douglas had spent a couple of weeks with him on Barnes Field, Long Island.

A strong bond of friendship had been forged between Douglas, Bill Barnes, and Shorty Hassfurther during those two weeks. They had been horrified, then angry when they learned that Douglas had been cashiered from the Royal Air Force. Now they wanted to get to him to prove that their friendship was something more than empty words.

Bill Barnes' bronzed face became grim and a little tense as he studied the scudding black clouds racing across the sky. A vision of that night two years before when he and young Sandy had been caught by a sand storm over the Syrian Desert flashed through his mind. Then he shook his head angrily and raised his hand above his head. The dispatch tower acknowledged.

The twin Diesels in Red Gleason's Snorter roared. A signal flashed and the big amphibian rolled forward. It streaked down the runway into the wind. The tail came up. The earth faded away beneath it and the' spinning landing wheels described an arc as the bracing members folded and swung up into their wells. Red took the thundering ship upward in tight spirals to level off at five thousand feet. The wind screamed along the streamlined fuselage as Shorty Hassfurther and young Sandy kicked their ships into the wind and joined him.

Bill Barnes' eyes sparkled as they ran over the instrument layout of the Silver Lancer. He felt a surge of pride as he told himself for the thousandth time that he was sitting in the greatest fighting ship in the world.

He touched the elevating and transversing screws of his telescopic machine gun and 37 mm. cannon sight, tested the radio control group and ran an eye over the Stark 1-2-3 flight instrument layout. He pivoted the infra-red-ray telescope which permitted him to sight along a beam of "black light" through fog clouds or darkness on its two-hinged supports, to test it.

His whole body was singing "as he stuck his booted feet into the rudder stirrups and opened the throttle. He cocked his head to one side as he released his brakes, and listened to the throb of his engines.

He was smiling to himself. He eased l the stick back and took the great ship into the air. The world he decided at that moment, was a pretty swell place to live in. His trip to China and his business with the Nanking government had been successful. Things were on the up and up. To-morrow they would pick up young Douglas at Ma'an and a few days later they would be back on Barnes Field on Long Island.

The yellow wheel-gear light and the green floating-gear light flashed as the amphibian gear folded completely into the fuselage and wings.

Bill threw his radio key and spoke to his men.

"Be sure your running lights are 0.K.," he said. "Watch out for the air currents over the desert. They're tricky. We'll cruise at two hundred and fifty. Shorty, you take the point of a V with Red on the right and Sandy on the left. I'll be a couple of hundred feet above and behind you. Keep plenty of distance; you'll need it. Signing off."

"Say, Bill!" young Sandy broke in, breathlessly. "Do you suppose I could pick up a good Arabian horse when we get to Ma'an?"

"How're you going to get him home, kid?" Bill asked, grinning.

"He’s going to let Douglas take his ship and swim the horse across the Atlantic!' Shorty Hassfurther offered,

"Naw," Red Gleason interrupted. "He's going to get a jumper and jump him across the Atlantic. Or, maybe, get that magic carpet some one used to fly around on.

"All right, smart guys," Sandy said, heatedly. "No one asked you what you thought."

"We just like to be helpful," Shorty said. "You know, do our daily good deed. Why don't you buy a camel instead. It-"

"Nuts!" Sandy said and threw his radio key.

The air was causing their compass needles to jiggle in crazy fashion as they passed above that flat, arid stretch of northern Arabia. From each dial on their instrument panels came a pale, phosphorescent glow. Their gyro and earth-inductor compasses, and turn-and bank-indicators were going mad as the hot, upward drafts of air bounced them around.

As the fury of the wind increased they had to clench their teeth and use every bit of concentration at their command to keep on their course.

The sturdy ships dropped into pocket after pocket, slapping them against their safety straps. Every moment was a fight; every twist and lurch and drop had to be compensated for.

Their ships would nose upward, suddenly, like an ocean liner riding a heavy sea, only to slide down again on the other side.

Then a sand storm came roaring at them like a giant monster. Bill checked his bearings while he tried to keep control of the Lancer, threw his radio key and gave his position to his men. The world became a yellow-and-black hell, with sand seeping through the locked overhead hatches of the four planes.

"We'd better get some altitude," Bill gasped into his microphone. "We may be able to get above this. Get up to fifteen thousand and hold the same course."

"You ought to be down on the ground on your favorite Arab steed, kid," Shorty panted into his microphone.

"Don't worry about me, you Pennsylvania kraut," Sandy gasped. "We'll be lucky if you don't crack up your Snorter." He flipped his radio key and began to feel his way even more cautiously. He was using every sense, relying more on his inherent touch and skill than on his instruments. He was crouching forward over the stick. His shoulders ached from being banged against the cowling and the rubber crash pad in front of him.

Suddenly, it seemed that a giant hand came out of the air from above to slap him toward the earth. He nursed the ship to an even keel, his eyes anxiously scanning his instrument board. He drew the stick back and talked to the Snorter. Terrific blasts of air and sand were beating against the windshield. His hands were clammy with perspiration. His whole body was wet. He threw his radio switch as a ruby light gleamed on his radio panel.

"Check in, all of you." Bill's voice came over the air.

They gave Bill their positions and all said they could not see one another's navigation lights.

"Hold 'em as you are," Bill said. "Try to keep on your course. We ought to be out of this soon. Signing off."

He pulled the Lancer out of a flat spin and tried to peer earthward-abysmal darkness, the swirl of sand around his running lights on his wing tips. He pulled the parachute lever and watched the flare take a dizzy course earthward. The whole world was a thing of swirling sand.

Far out in front of Sandy and Red, Shorty Hassfurther jerked the stick of his Snorter back into his stomach to bring it out of a dive. It was being buffeted about like a leaf in a gale. His body ached from being thrown against the cowling. His stomach ached from being slapped against his safety strap. His heart was pounding from exertion. Sand had crept through his hatch to settle in his eyes, his mouth, even down his neck. He shook his fist at the weather and cursed it as only he could curse at such a time. He nursed the ship back into level flight, only to have it picked up and slammed down another four hundred feet. The storm raged and roared without a let-up. He wondered how long his Snorter could take such a buffeting. Then it occurred to him that he didn't care much. He was getting so tired that nothing mattered.

Off to the right, Red Gleason was fighting with a laughing tenacity that was characteristic of him. He whipped his ship out of pocket after pocket while he tried to accompany the scream of his motors with his own voice.

The motor, he told himself, was singing bass and the screaming wind that brought that high-pitched whine to his props was singing tenor. He was carrying the baritone, although he couldn't carry a tune. He gave an excellent imitation of two drunken men singing in a bathroom as he studied his compass and checked his course again. His head was ringing like a blacksmith's anvil from the beating he had been taking. He threw his radio key and a roar like the bellow of a bull greeted him.

"No radio, no peace, no ceiling, no nothin'," he said to himself, through clenched teeth, and settled back to the business of taking his Snorter through that storm.

Suddenly, the sand and wind no longer beat at the windowpanes of non-shatterable glass. Bill flipped his radio key and shouted, "Red, Shorty, Sandy!"

The three of them gave the all-clear signal. Bill's breath hissed between his teeth as he exhaled. His eyes swept, from his map and chart to the instrument board as he asked them for their positions. He checked them against his own and gave them their course. Ten minutes later they were back in their original positions.

" All right," Bill said to them. "Take it easy. Hold your course. I'm going to break out the infra-red-ray telescope to take us in the rest of the way."

He brought the telescope out of its recess in the instrument panel and threw the switch. He looked into the eyepiece, which was not unlike the old-fashioned parlor stereoscope. Ahead the pitch-black night became as day as the beam of infra-red rays projected themselves artificially into the darkness and the electron telescope enabled him to pick them up.

As he started to adjust the lens, a sharp, staccato noise came, out of the night. It brought him straight up in his bucket seat, his eyes wide.

He had heard that noise too many times before not to know what it was. And he knew by the sound of that staccato chatter that the machine guns he heard were not the Brownings set in the engine housing of his Snorters.

He could feel bullets drumming into the wing and tail surfaces of the Silver Lancer; he could feel the big ship tremble under the impact. He pulled the control column of the Lancer back into his stomach as he heard screaming props and thundering motors dive beneath him. As the nose of the Lancer streaked upward, he threw his radio switch arid began to chant the call letters of his men. Red Gleason's voice came back to him first. And he could feel the blood in his body turn to ice as he heard Red's voice.

."Bill!" Red gasped. "Bill! They got me. I still have control, but they got me bad through the shoulder. I'm trying to climb."

Bill's hand was a ball of muscle and steel around the control column of the Lancer as he tried to pick thoughts out of his whirling mind.

"Can you make it? You aren't going to faint?" he asked quickly.

"I'll be all right if I can get above 'em," Red said, his voice steadier. "I'm getting hold of myself now. One bullet almost tore my shoulder off. The pain is easing now."

"Turn on your oxygen tank and get up to twenty-five thousand," Bill said. "They're coming back!"

"Bill!" Shorty’s voice cut in. "They made a sieve of my Snorter. They are flying without lights. I thought I heard their engines, but I wasn't sure. I was sure when bullets began drumming into me."

"Get up with Red!" Bill barked. "Stay beside him. Keep contact by radio. Leave your navigation lights on. Where's Sandy?"

"I'm riding all right, Bill," Sandy broke in, his boyish voice high-pitched and strained. "They came out of nowhere; Bill. I think there are about six or eight of them. I can hear them climbing. They're trying to get above us."

"You get up with Red, too," Bill said. I’ll try to find them with my telescope. 'Then I'll join you."

"Look out for a crash, Bill," Shorty said.

"I’ll watch it," Bin growled. His whole body was burning with anger now. It had been the most murderously unfair attack that had ever been made on him. His body and mind were seething with rage. He neutralized the controls of the Lancer and cut his engines. He could hear the drone of six or eight engines below him to the north. He kicked his rudder and stuck the nose of the Lancer down. He peered into the eyepiece of the infra-red telescope, as he thought he had the nose of the Lancer 'n the ships returning to their murderous attack.

As the telescope picked up the eight lanes racing upward, Bill gasped and continued to peer with unbelieving eyes. The ships were fast, rugged one-seaters with flat, short wings, lean fuselage, stripped down undercarriage and mighty power plants. But those things were not what made him gasp. He gasped because he could see the squadron insignia of the Royal Air Force painted on the sides of the fast little ships!

As fire and orange flame jetted from the machine-gun troughs along the engine housing of the eight ships, Bill jerked the control column of the Lancer back into his stomach and stuck the nose upward to escape that hail of lead. He could feel the Lancer tremble from em to stern as bullets drove into the tail assembly. Then he was away from them. He leveled the Lancer off and began to spiral upward.

His mind was a maelstrom of thought. Why had a portion of a squadron of British planes attacked him? He wasn't sure, but he believed that the insignia he had seen was the insignia of a squadron stationed at Ma'an.

Then all of that left his mind as he thought of Red Gleason. He flipped his switch and made contact with Red on the radio.

"How are you coming, fella?" he asked him anxiously.

"I'll do, Bill " Red said weakly. "But I'm losing a lot of blood. I'll have to sit down soon."

"Do you think you can make it to Ma'an?" Bill asked. "It's a half hour. It will be dawn by then, We'll stay at twenty-five thousand until just before we're ready to land. It will be safer than landing on the desert, with those ships over us. Do you think you can make it?"

"I'll make it all right," Red said. "Three hundred miles an hour," Bill ordered. "Keep your radio open and shout if you think you're going to be in trouble, Red."

"0. K.," Red said. "Bill!" Sandy said excitedly. "I can see those planes streaking off to the west with their running lights on. They tried to get up to us, but began to wallow at about twenty-two thousand feet. Who are they, Bill?"

"'They were British army planes," Bill said grimly. "And the pilots wore British uniforms. I can't figure it out."

"Shall I follow them, Bill?" Shorty asked quickly.

For a moment Bill hesitated. Then he spoke with his usual decisiveness. "No," he said. "Let ‘em go. They might gang you. And we’ve got to stay with Red in case he has to land."

DAWN was creeping out of the east when the Silver Lancer and the three Snorters circled the field at Ma'an twice while they studied the wind sock and the layout of the field.

Five minutes later Bill led the way in. He had set his brakes, killed his engines, and was over the side before the man in the uniform of the Royal Air Force reached his side.

"Oh, Barnes! Mr. Barnes!" the man called as Bill ran toward Red Gleason's Snorter. Bill knew that Red must have fainted because his twin props were still whirling after he set his brakes and the ship came to a halt. He turned his head and waved a beckoning hand at the man in the light-blue uniform.

Bill's face was white, and the muscles in his cheeks stood out like whipcord as he dived into the front cockpit of Red's Snorter

Red was curled up over his stick, and his left shoulder was a sodden mass of red. Bill's breath whistled through his nostrils as he slipped the catch on Red's safety strap and lifted him bodily out of the cockpit and tenderly slipped his feet to Shorty Hassfurther.

The eyes of the man in the sky-blue uniform widened with horror as he saw the blood-saturated body of Red Gleason. But he didn't forget why he had been sent out to greet Bill Barnes.

He saluted and began, "Wing Commander Kestrel sends his compliments to Mr. Barnes and his men, and re--"

"Stow that!" Shorty Hassfurther snapped at him. "We need an ambulance. Hop!"

Kestrel's adjutant stared at Shorty for a fraction of a second. "Right!" he exploded as he swung on his heel and sprinted toward a group of buildings.

Bill Barnes had cut away Red's white overalls and was packing gauze against his horribly mutilated shoulder. Shorty was doing what he could to help, while Sandy looked on with that touch of sadness and horror in his eyes that bespoke his youth.

"Do you think it's very bad, Bill?" he asked.

"Plenty bad," Bill growled. "The bird who did that is going to pay for it. Red's lost a lot of blood, and I don't see how the bone can avoid being shattered."

He glanced up as an ambulance came clanging across the field with two or three men hanging on the back - then back at Red. His hard eyes became misty as he gazed at the calm stillness of Red's white face.

"Guts!" he said, half to himself. "He has what it takes." He knew what pain that last forty-five minutes must have cost Red. He knew how he must have struggled to fight off unconsciousness until he had his ship down safely.

"That," Shorty Hassfurther said, his voice husky, "is something he learned in France when they used to give us orders to bring our ships back. They didn’t care if we got shot through the head. That was all right with them. But they needed the ships."

Bill and Shorty lifted the inert form of Red into the ambulance, hung on the back step while it clanged its way across the field to the hospital.

Ten minutes later they saw Red wheeled into the operating room, his face as white as the sheet that covered him.

BILL BARNES' face was a thundercloud as he faced Wing Commander Kestrel across his desk. Both he and Shorty had shaken the commander's hand.

"How did this thing happen, Barnes?" Kestrel asked, "Is he badly hurt?"

"We left Sandy with him," Bill Said. "He is still under the ether. We don't know how bad it is. But some one is going to pay for it."

"Could he have shot himself accidentally while he was in the air?" Kestrel asked. "They told me it was a bullet wound."

"It is a bullet wound," Bill said grimly. "It's a wound from a machine-gun bullet fired from a Royal Air Force plane by a man in British uniform!"

"I say!" Kestrel exclaimed. He started to rise from his chair, then sank back again while the color drained from his face.

" A bullet fired from a British plane by a man in British uniform," he said stupidly.

"What about it?" Bill barked. "We were about two hundred miles from Ma'an when eight one-seater biplanes dived on us with all their machine guns yammering. Luckily Gleason was the only one who was hit. The rest of us managed to get out of their line of fire. Hassfurther and Sandy joined Gleason at twenty-five thousand feet. I stayed down to learn who had attacked us."

"Eight one-seater biplanes," Kestrel repeated. He talked like a man under the influence of a strong drug. "How could you tell who they were at night?"

"My Lancer is equipped with an infrared-ray telescope," Bill said. "I could see them as plainly as I could in the daytime. I saw their uniforms. They were not wearing overalls. And I saw the British cockade and the squadron insignia checked the insignia with a plane on the field a few minutes ago. They are the same."

"Yes," Kestrel said, like a man who is tired beyond endurance, "they are the same. About two hundred miles northwest of here?"

"That's right!" Shorty barked. Kestrel looked at him for a moment as though he didn't see him. Then a faint smile flickered on his twisted lips.

"I'm sorry this has happened, Barnes," he said. "I am more sorry than I can say. Things are happening so fast I can't keep up with them mentally. I must explain to you, I'll try not to bore you. You must be patient. I hope this won't make a difference. I've been hoping since I learned you were coming you would help me, Barnes:"

"How did you know I was coming?" Bill asked.

Kestrel's eyes left Bill's and traveled upward to a point on the wall across from Bill, then shifted back to Bill's face, then to Shorty's. He shook his head sadly as he spoke.

"I learned it from a letter Douglas was writing to you, Barnes. We found it in his rooms in town. He-he-,--"

"What about Douglas?" Shorty snapped again. "Where is he? We know about his court-martial. Where is he?"'

"He's dead," Kestrel said. "He was murdered night before last!"

"Murdered!" Shorty said slowly. His own face was white now, and he was thinking about the parents of young James Douglas. He was thinking about the tragic death of James' older brothel during the War. Thoughts rushed through his mind. He tried to speak and found that he couldn't,

Kestrel's eyes softened as he saw the tragedy written on Shorty's hard face. He put up a hand and spoke softly.

"Let me tell you about things," he said. "I'll lay all the cards on the table. You'll understand if you let me tell you the whole story. It can't be told in halves. You wouldn't understand if I told you that way."

Bill and Shorty sat spellbound while Kestrel unfolded the whole weird story. At times Kestrel stopped as they glanced at one another incredulously. He told them of the unrest of the natives and the attempt to mutilate the sacred Dushara. He told them of the theft of eight British planes and the cashiering of young Douglas. He told them all he knew up to the time he had gone to bed the night before.

"Those planes that attacked you," he said, "were the ones that were stolen. It is as I thought: some one is working from the inside. They knew you were coming. They sent out those ships to stop you. But who sent them? And from where did they come? Those two things, gentlemen, are the things that confront us. If we can find out those things we will learn who murdered your friend.

"I admit now I was a fool to listen to the charges against him. He was not guilty, and he was determined to prove it to us. The things he learned cost him his life. What were they?

"If I had not been such a fool he would be alive to tell us. One of your own men has been dangerously wounded through no fault of his own. It seems that you are drawn into this thing without being able to help it. The long arm of the man behind it reached all the way to China to enmesh you in a fiendish plot that may cost thousands of lives. I need your aid. I beg you to work with me. By working together we can each satisfy our own interests."

"We're in, all right," Bill said. " And we're going to stay. Have no fear about that. We want to know who murdered Douglas. And if Gleason doesn't pull through-"

He stopped, unable to go on.

"What about Douglas?" Shorty asked. "Will he be sent home?"

'I have cabled his parents," Kestrel said. "I will do what his parents wish."

"I'll take care of that," Shorty said abruptly. "They are friends of mine, too."

BILL and Sandy paced nervously up and down the anteroom of the hospital. Shorty Hassfurther, whose anxiety was even greater than theirs about his best friend and War-time pal, sat reading a newspaper and mentally cursing his nerves.

An interne had told them that they would not be permitted to see Red that day. He was so heavily doped, he said, he would not be able to recognize any one.

But they were waiting to get a report from the doctors who had worked on his shoulder in the operating room. They knew it was very possible that his left arm might be amputated.

Major McCardell, in command of the medical unit, made a report to them. He was an elderly man with a long and naturally dour face. Bill's heart fell to his boots when he made his appearance and Bill got a glance at his face.

"I'm glad to be able to tell you," he said, "that it isn't as bad as it looked at first. He will not lose his arm and we will be able to build up the bone very satisfactorily. It will always be a little stiff, but he will not be a cripple. He is doing very well considering the shock and frightful loss of blood. We will have to keep him extremely quiet for a few days. It is possible we may need a blood transfusion or two."

"That's where I come in," Shorty said gruffly. "My blood has been tested for him. They used my blood for him once before."

"That's a relief," McCardell said. : "We may need you, Hassfurther."

"Wing Commander Kestrel has given us quarters on the field," Bill said. "Will you send an orderly to us as soon as we can see Gleason?"

"I will." McCardell nodded. " And I'll keep you informed about any developments. Don't worry about him; that won’t do any good."

"0.K." Bill smiled. "We know you're doing your best."

Bill reported to Wing Commander Kestrel before he took the Silver Lancer into the air a half hour later.

"I'm going to look the land over," he said to Kestrel. "I may see something that will give me an idea."

"Some one has got to get an idea pretty quick, Barnes," Kestrel said. "If we can find the place they are hiding those eight planes and where they took the cargo from those seven caravans, we'll be a long way toward a solution. Even my own men are getting jumpy now. They know that somewhere there are traitors. We are like a house divided. Everyone is suspicious of every one else." He wiped his face with a handkerchief, and Bill saw that his face was white and tense, and strained to the breaking point. "You'll want to go through Douglas' things with Hassfurther?"

"When I come back," Bill answered shortly. "Hassfurther will remain here on the field. Sanders is going with me."

Bill whipped the Silver Lancer into the air in a manner that had the grease monkeys and mechanics on the field wide-eyed. As he spiraled upward, they stood in little groups hardly able to believe what they saw.

At five thousand feet Bill leveled off and looked over the side as Sandy's voice came over the inter-cockpit phone.

"Say, Bill," Sandy said, "I wonder where a fellow would go to buy a horse?"

Bill didn't answer him. He was searching the boulder-strewn desert below with his eyes. Here and there he could see the tents of the nomad Bedouins with their camels grazing near by.

"How much do you think a good Arabian horse would cost?" Sandy persisted.

"How the deuce do I know?" Bill growled. "Why don't you get yourself a harem instead?"

"Not for me," Sandy said emphatically. "I'd rather have a horse-any day than a lot of women!"

" All right, all right," Bill said. "Now shut up. I didn't come up here to talk about horses. Keep your eyes on your altimeter. I'm going to cut north over the Dead sea."

They raced the length of the Dead Sea into the Jordan Valley before Bill banked the silver ship around and came back over the precipitous cliffs on the eastern shore. Black basalt from volcanic eruptions blended with the bright red of the sandstone cliffs. Where wind and rain had chiseled away portions of the cliffs, great columns stood erect with black crowns on their heads, which faded into red, until, at the base, the bright-blue waters of the Dead Sea lapped at their feet.

The narrow chasm, through which the Wadi el Mojib flowed into the Dead Sea, flashed below their wings, and here and there they saw bright-red patches where the fertile land had been newly plowed. Scattered along the wadies were camps of Bedouin goat-hair tents.

Gliding down to a thousand feet as they entered another valley, they could see the terraced gardens and orchards below El Kerak.

Then they were back over the vast expanse of desert plateau that was the northernmost extremity of the Syrian Desert. The tan-and-yellow desert was bare of trees or color, except where a wadi cut its surface. To the east the desert rolled away interminably; and to the west a low range of hills towered into the air.

Bill stuck the nose of the Lancer up, and just cleared the tops of the scrub-oak thicket on the westerly range with his altimeter at five thousand feet. They both gasped in amazement as they sped between the dizzyingly colorful twin ranges where Petra nestled. To the west stretched the deep expanse of the Araba, blue-tinted, remote and forbidding. The yellow, tan and ivory sandstone changed to vivid rd as they flew between the two ranges of fascinating shapes and color.

"That is Petra, kid," Bill said, pointing. "Kestrel gave me a map. The large building in ruins used to be the castle of Pharaoh’s daughter, and the hill above it is El Habis, the Acropolis Hill.

"Over there on the left is El Khubdha and El Der. The river below us is the Wadi es Siyagh. It's the only outlet from Petra, except Es Siq, where Douglas was murdered two nights ago. But it's impassable to caravans."

"How did that caravan get out of Petra?" Sandy asked.

"It didn't," Bill said grimly. "It's in here some place. That highest peak is Jebel Harun. The building on the top with the white dome is the tomb of Aaron, and the place where the Dushara is kept. Some one tried to get in there the other night and mutilate the Dushara. The natives, according .to Kestrel, are half mad because of it.

"That great flat mountain over there is Umm el Biyara, Petra's most ancient stronghold. It tells in the Bible how David wanted to storm the Edomite stronghold in his day. There used to be a single path cut in the side of it so that men could get to the top. But erosion has worn it away."

"We could almost land on there, couldn't we, Bill?" Sandy asked.

"Almost is right," Bill said. He flew lower and inspected the great, flat surface. "It might be done, but I don't want to do it. It was impregnable in its day, and still is, except from the air. The little mountain beside it is El Habis. That's an unfinished tomb. The rock-cut couloir was the only way to the top of Umm et Biyara. After the men had taken their women and children and eiders to the top they could close off the path with a gate. They had cisterns on the top - you can still see them - to catch and hold water."

"Gosh, Bill," Sandy said. "You know a lot; don't you?"

Bill swung around in his seat and looked at Sandy suspiciously. But Sandy was serious.

"You aren't trying to kid me, are you?" Bill asked.

"No! Gosh, no, Bill. I'm really interested."

The air had become bumpy now above the crags and caverns of Petra. Bill yanked the stick back and zoomed the big ship upward.

"The best way to get into that place is on a horse, Bill," Sandy said.

.'That's the way we'll come next time," Bill answered. "I'm going to circle this place now. Those caravans and those eight ships have to be some place. Button up your lips. I'm going to open the Lancer up wide and cover as much territory as I can."

VII - STRANDED

THE RED limestone hills surrounding Petra gave way to the great barren wastes of the desert as Bill opened the throttles of the Lancer and circled westward. Here and there among the boulder-strewn stretches of desert west of Ma'an they could see Arab encampments with horses grazing where there seemed to be no vegetation.

As the ruins of an old Arab citadel flashed beneath their wings, Bill stuck the nose of the Lancer down and circled back. No living thing moved within the crumbling walls. Outside, heat danced from the sun-scorched steppe as the sun crept higher into the heavens.

Twice they saw large bands of roving Bedouins astride sturdy Arab horses. Flying low, they saw the fierce nomads of the desert unsling their rifles and felt the drum of their bullets as they pounded through the metal skin of the Lancer. As they nosed upward the tribesmen shook lances and yataghans at them until they were mere specks on the desert.

"Take her for a few minutes, kid," Bill said to Sandy. "There is something screwy about our fuel tanks. I told 'em to check 'em when we landed this morning. We may have picked up a couple of punctures last night."

Sandy held the Lancer at three hundred miles an hour while Bill checked the fuel lines and tanks. He checked and rechecked his instruments to find their position.

"We're almost two hundred miles from Ma'an, Bill," Sandy said." And she isn't pulling the way she ought to. I just adjusted the props and it didn't do any good."

"Stick the nose on Ma'an, kid," Bill said. His eyes were worried as he scanned the instrument panel. "Give her some more juice."

Sandy opened the throttles another notch, and the air-speed indictor crept up to four hundred miles an hour. Then be leaned over and inspected the extension handles of the two .50-caliber machine guns at his right and left and fingered the trigger cables. The circular dials of the automatic counters showed capacity filling.

For fifteen minutes Sandy held the nose of the Lancer pointed at the horizon, and Ma'an. Perspiration dripped down his face as the sun became hotter and hotter. He half closed his eyes to protect them from the intense glare.

Suddenly his eyes flew open and he sat up in his bucket seat with a start. The far-away roar of airplane motors came faintly to his ears. He thumbed the sun, but could see nothing. He looked back and up on both sides, and still could see nothing. He saw that Bill was bent over so that any sound would be drowned by the roar of the twin Diesels in the Lancer: He bent his head and cocked it to the right, then to the left.

It sounded as though the planes welcoming toward him from his starboard side. He scanned the air above and below the starboard wing. The sound was certainly growing louder and coming closer. He decided he had better speak to Bill. He hesitated another minute while he listened.

And while he listened it happened! Two formations of three fast, rugged, one-seaters were diving out of a wisp of fleecy clouds a thousand feet overhead, their might); power plants roaring at high-pitched crescendo as they dived.

Sandy gasped in horror and shouted Bill's name three times in the inter-cockpit phone. White streamers of lace floated through the air as machine guns began to yammer their song of death.

As Sandy jammed the control column forward into a vertical dive, Bill grabbed at the controls and yanked the throttle wide.

"Break out that swivel gun!" he roared as the Lancer plummeted toward the desert at terrific speed. "Don't miss when I come back up in a loop!"

Sandy broke it out and pushed back the sliding hatch. He ran the gun across the track while he nearly choked, with excitement. His freckled face was dripping with perspiration. He held the palms of his hands against his head for a moment to lessen the pressure as the Lancer continued to plunge earthward.

The two V formations continued their dive, following the Silver Lancer toward the desert. Bill's mouth was a firm, hard line across his face as he glanced back and up. He held the stick forward until the Lancer was almost at terminal velocity. Then he swung the nose up with the touch of a master. Machine-gun bullets drummed into the tail assembly as the Lancer came up and over on its back.

Bill centered the controls and rolled light side up as the six light-blue ships dived under him. He could see the cockade of the Royal Air Force and the same squadron insignia he had seen on the ships that had attacked them the night before.

Opening the throttle of the Lancer wide, he stuck the nose up in an abrupt climbing turn until he almost stalled. He kicked his rudders and rolled to the right. He was back on his original course with the nose of the Lancer pointed toward Ma'an.

He cut his throttles while he studied the six blue ships. The men piloting them wore helmets, goggles and overalls, . and he saw, as they came out of their dives in a precise formation, that they could fly.

A thousand thoughts raced through Bill's mind as he watched them spiral upward and return to the attack. He knew he was justified in returning their fire. Yet he hesitated. He knew he could open the throttles of the Lancer and run away from them. He could land safely at Ma'an, but he would still know nothing about their base.

He could climb to a ceiling they could not reach and follow them to their base, but he was worried about his fuel supply. If his tanks had been punctured the night before and he was forced to land, he and Sandy would be at their mercy.

Then one of the blue ships was on his tail again. He heard the tat-tat-tat of its machine guns, followed by the fire of another. He could feel the bullets lashing through the Lancer's tail assembly and creep forward. He pulled the stick back and sent the Lancer skyward in a desperate zoom.

"All right, kid," Bill shouted into the telephone. "Let's dish it out!"

He heard Sandy's swivel gun chatter as the six rugged biplanes closed in on them from every side. He gunned the Lancer and pulled away. The light-blue ships tried desperately to stay on his tail.

"Now, kid!" he roared. "We'll take it to 'em!" He whipped upward in a chandelle and dived head-on at the six rugged one-seaters. He dived with his two .50-caliber guns yammering. But his speed was too great for accurate fire. The blue ships dived and zoomed and skidded to get out of his mad path.

A blue ship came under his sights for that fraction of a second that is enough. His finger fastened down hard on his gun trips. He raked the blue ship with a withering fire. The pilot's head jerked upward, then slumped forward on his chest as it became a mask of blood. The plane slipped off to the right and began a fluttering descent to the desert, until the nose fell and the tail began to spin.

Bill gunned his engine again and came over in a normal loop on the tail of another ship. His line of tracer smoke curled above the head of the pilot. His bullets crashed into the fuselage and crept-forward into the engine block. Little wisps of smoke rose along the engine housing. Then orange flame raced out and back into the face of the pilot.

As Bill zoomed upward he heard Sandy's swivel gun chattering again. He glanced back over his shoulder, and saw that Sandy's eyes were gleaming like balls of fire in a face that was streaked with black.

Then the air seemed to be filled with flashing, slashing blue planes. They darted about the Lancer like wasps about an enemy who has disturbed their nest. They were everywhere, charging in from all angles, trying to get the Lancer in the vortex of their fire.

Bill whipped the Lancer through the air with the speed and precision of an automaton. He knew that the Lancer was taking a terrific pounding, and he knew that one bullet in the reserve tank on which he was running might be fatal. But he was determined to fight it out now. He was determined to fight until he had the knowledge he wanted. And that meant he must drive off those four planes so that he could land beside the pilot who had bailed out of his burning plane.

As another blue plane came under his sights his finger clamped down on the trip of his 37 mm. cannon. A half dozen roaring barks sounded above the din of throbbing motors and yammering machine guns.

What had been a sturdy biplane became a great cloud of black smoke, stabbed with streaks, of saffron and crimson. Ribbons of bright orange shot out of it as it broke in all directions. The three ships behind it zoomed upward to get out of the path of the flying debris. Wings and fuselage hurtled through the air as the shells of the 37 mm. gun struck the engine block and detonated. The engine dropped from the black cloud and raced toward the desert. A gust of wind struck the black cloud of smoke and lore it apart. All that was left of the biplane and its pilot were bits of cloth and metal falling earthward.

"That ought to teach 'em something!" Sandy gasped. ,

But Bill was too busy avoiding the six streams of death that were aimed at him to answer. He grimly counted three in his mind as he came up in an outside loop and dived. Again his fingers fastened down on his machine-gun trips. The pilot of the ship that was under his sights tried to stand up and walk off into space. Or so it seemed. But he would never try to walk again. His body had been made into a sieve, from which his life's blood poured out into the cockpit as the ship plunged toward the silent, endless desert.

It was then that the other two biplanes decided that discretion was the better part of valor. They stuck the noses of their ships down and opened their throttles wide as they saw the fourth of their comrades go to his death. Their faces were white and frightened as they glanced back and up over their shoulders.

Bill wiped the perspiration out of his eyes as he watched them go. For an instant he had an almost overwhelming desire to follow them and tear their ships to pieces with his bullets. They had tried to gang him, thinking their superior numbers would give them an advantage he could not overcome.

The blood pumped through his body like liquid fire as he watched them go. They were the murderers of young Douglas. And they had tried to murder him. He debated whether or not it was his duty to go after them. Then he decided against it. It he could pick up the man he had seen bailout of his burning ship he would take him back to Kestrel, and Kestrel would make him talk.

He took his eyes off the fast-disappearing ships and scanned his instrument panel. The blood in his body, which had been boiling with rage a moment before, seemed to freeze.

His fuel gauge showed zero as his engines began to spit and sputter! He idled them out and tried to hold his altitude while he studied the barren wastes of sand below them.

"Gosh, Bill." Sandy's voice came to his ears. "We'll never get out of here."

"Shut up!" Bill answered as he threw his radio key and began to chant Shorty's call letters into the microphone.

But Shorty's voice did not answer. No sound came back to Bill but the faint crackle of static. He twirled the volume, wave-length control, and the master tuning control to get the radio station of the Royal Air Force field at Ma'an.

As an answering voice came back he spoke his name once. Then all was silence. He stared at his radio controls and twirled them while he continued to chant the field’s call letters into the microphone. But no voice answered except Sandy's.

"It's dead, Bill," he said as Bill threw his telephone switch.

"Get out some glasses," Bill said to him. "See if you can locate Ma'an. I can't see it because of the mountains to the east. Perhaps you can find it with the glasses. I'm trying to stretch out our altitude, but we're almost out of it."

"I can see where it is, approximately," Sandy said in a moment. "But it's a long way from here. What do you suppose is wrong with the radio?"

"Something shot away," Bill said curtly. The cold hand of fear clutched at his heart as he gazed at the interminable sea of sandy hillocks that stretched on and on, forever.

He knew that unless one of Kestrel's men sighted them in that vast expanse of sand it would be their last resting place. A man might fight his way through to water and civilization, but his chances would be small.

He threw a switch and watched his instrument panel until his wheel-landing-gear light and float-landing-gear light burned. Then he flattened the Lancer out until his wheels were just kissing the sand. They struck the irregular surface at eighty miles an hour, with flaps set well down. The engines gave their last sputtering gasp as Bill threw on his wheel brakes and cut his switches.

Suddenly he sat bolt upright in his bucket seat and probed the air above him. Then he tore out his radio headset and shouted at Sandy.

"Get your gun ready, kid!" he said. "Those two planes are coming back. They must have seen us banking down and came back to find out what was the matter." He went over the side of the Lancer with a bound, saying, "I’ll get the submachine gun and the rifle out of the emergency locker. Be ready; they’ll come shooting."

They came shooting! They came roaring down like two attack ships with all four or their machine guns yammering and their engines wailing in protest.

But they had not counted on the flexible gun in the rear cockpit or the Lancer. They had expected to find their two victims helpless.

Nor could they shoot with the accuracy young Sandy displayed. After that first terrific onslaught they zoomed upward as Sandy's .30-caliber gun sent burst after burst into them.

"Gosh, Bill," Sandy said after that first attack, "if we could only use the cannon!"

"Take this Thompson gun," Bill said grimly. "I'll handle your gun. They'll be back in a minute."

But they didn't come back. Bill watched the two circling ships, waiting ( for one or them to rock his ship slightly t and extend an arm upward, meaning I to attack.

Instead, the leader or the two ships rocked his plane violently and "peeled off" toward the south, indicating that he was going out or action. The other one followed close on his tail. They had had enough or the accurate shooting of Bill Barnes and Sandy.

"They'll probably come back with reinforcements," Bill said. He ran his tongue across his dry lips and was startled as he caught himself doing it. He knew that the terrible hands or desert thirst were flicking him. He knew that unless one or Kestrel's men located them they would never be able to get out of there alive.

But he kept those thoughts to himself as he looked at Sandy. He knew that it would be useless to tap the radiators for water because or the chemical mixed with it. It would make them both deathly sick. He thought about two French airmen who had been forced down in the Sahara. They had kept themselves alive by scooping the dew off their wings in the morning and putting it in a container.

That, and a thousand other things, flashed through Bill's mind in those first terrible minutes. Then he got hold or himself and grinned at Sandy.

"We'll have to get under the ship, kid," he said, as though this was something that happened to them every day. "We can take advantage of the shade. We won't get so thirsty. KestreI and Shorty will have men out looking for us in no time."

"I'd like to get hold of that grease monkey who said our fuel was 0.K.," Sandy said.

"Perhaps," Bill said slowly, "he told us that with a purpose."

THE NEXT FEW HOURS were burned into their brains indelibly by the desert sun. When it seemed that they could stand no more, the sun turned on its most scorching rays. At midday they lay panting below the float of the Lancer, moving every few minutes to stay within its shade. Their lips were beginning to crack and their tongues swell into things that felt like huge, dry sponges.

Bill tried to tinker with the radio. But each time he thought he had mended the defect and threw the switch, no crackle of static came to his ears.

"Gosh, Bill," Sandy said at two o'clock, "do you suppose they'll look for us? I-I-"

"Sure, they will," Bill said hastily. He gazed at Sandy's burning eyes and cracked lips and turned his head away to hide the thing that came into his own eyes. "They're probably scouring the countryside now. They may not pick us up until morning. But they'll find us. It gets cool out here at night. We'll be able to get water then by scraping moisture off the wings. Keep your chin up, kid. We've been in tighter spots than this one."

"Oh, I'm all right," Sandy said, trying to laugh. But it wasn't much of a laugh. It was more like the hack of a consumptive. "We--we'll be laughing about how thirsty we were in a few hours."

"That's right, kid," Bill said. But he knew it wasn't right as he anxiously scanned the sky. He knew it would be a long time before they laughed about that day-if they ever laughed again.

In the late afternoon Bill broke out some chocolate from the emergency equipment in the tail locker of the Lancer. And he jotted down in his memory to the effect that if they ever did get out, in the future the emergency equipment would include a certain amount of water.

The sun was poised, ready to plunge into the sea of sand to the west when Sandy let out that first startled exclamation and began to shout at Bill, and point.

Bill followed the direction in which he was pointing, and his eyes narrowed after their first moment of astonishment. Between two hillocks of sand they could see a half dozen mounted men. They wore the bright-colored mantle and head cloths of the desert nomad, and Bill could see that they were armed to the teeth with lances, rifles, shotguns and yataghans. Then they were gone from view. .

"Wait a minute, kid," he said. "Stop yelling! They may not be so friendly. Remember, they took shots at us before."

"I'd do anything for some water, Bill," Sandy said desperately.

"If they're unfriendly you don't want to fall into their hands." Bill answered sharply. "Kestrel said the natives were ready to revolt. It may be a tribe on their way to join others in the revolt.

Bedouins are notorious for their methods of torture. Get into the rear cockpit of the Lancer. I'll get in the front. If they come toward us in a friendly fashion, stay in the cockpit and have your gun ready. If they come shooting, let 'em have it."

As twilight settled upon them, the desert became a place of exquisite color for that brief period between daylight and dark. Then the day's fierce heat began to radiate away through the clear, dry air, and the chill of night crept upon them. In an hour's time the moon was high overhead, making the night nearly as light as day.

Suddenly Bill sat up in the front cockpit and threw the switch on the infrared-ray telescope. He had seen what he thought were moving forms on the crest of the hillock ahead. He took one look through the telescope, then spoke to Sandy.

"They're coming, kid!" .he said. "There are forty or fifty of them all around us. I can cover the front with my machine guns. You'll have to take care of the rest. They’ll charge on horseback. Use your-"

That was as far as he got when that horde of wild tribesmen came charging over the hillocks of sand from every side, their; robes flapping out behind them, their guns spouting fire and death, their horses driven half crazy by their high-pitched screams.

Bill's finger came down on the gun trips of the two .50-caliber guns in the nose of the Lancer as that first mad wave reached the crest of the hillock. His guns cut a path through the charging tribesmen before they began their charge. As they tore down the side of hillock, out of range, he snatched the Thompson gun from the deck and swung it in an arc.

Behind him, Sandy ran the .30-caliber gun over its track with the swift precision of a trained gunner. Horses and men fell in screaming heaps as his bullets tore into them.

The desert night became a place of horror as the deadly fire of the two machine guns cut down the charging zealots. Yet, on they came, shooting from the saddle, screaming their chant of hate and war.

When they were within twenty yards of the Lancer the thin line wavered. Horses and men piled up in struggling, howling masses. The unwounded men behind them could not advance. For an instant they hung there, returning the machine-gun fire with poorly placed shots from their rifles.

Then they broke and went streaming back over the hillocks, with half their number dead or dying. "

"Take it easy, kid," Bill said. "They'll be back. You'd better get some more ammunition ill your gun while you can."

The horrible screams of the wounded horses and men nearly drowned out his words. An occasional shot pinged into the Lancer from behind the hillocks.

"Gosh, Bill," Sandy said. "I wish they'd go away now. Look at that horse over there. It's a beauty. I could get it if I dared get out."

"You stay where you are, you half-wit," Bill growled. "You don't need a horse; you nee a nurse."

Bill's hands were trembling and his whole body ached from loss of sleep and nervous excitement as he checked over the ammunition he had left for the submachine gun. He found that he had just enough to stand off another charge such as the last one.

"How about your ammunition, kid?" he asked Sandy.

"Not an awful lot left, Bill. One belt." Bill shook his head angrily, then peered through the infra-red telescope again. The Arabs had stopped firing now, and he could see no movement beyond the hillock. He debated with himself for five minutes about the course he ought to pursue."

Listen, kid," he finally asked, "can you ride that horse?"

"Ride him!" Sandy answered. "Look at him, Bill. He's still standing there like a statue over the body of his master. You know I can ride him. I learned how to ride horses right after I learned to walk. I~"

" All right," Bill said sharply. "I'm going to give you a chance to ride him, Kestrel or Shorty will never find us here before that gang of bandits out there finds a way to slit our throats. It can't be more than twenty miles to Ma'an. If you can get into the saddle and get through that first line of Arabs you ought to make Ma'an within a couple of hours. An hour after you leave I'll turn on the landing lights of the Lancer to help you find me from the air. Don't let Kestrel send a lot of planes out here to crack up when they try to land.

"Just tell Shorty the situation and come with him. He'll get in some way. You can bring enough fuel with you to get the Lancer out of here. Take an automatic and the rifle with you, and be ready to shoot when you ride over that rim of sand. Then ride!"

"What about you, Bill?" "I'll be all right, if you get through safely. I have enough ammunition to hold them off .for a couple of hours."

"Suppose they charge in the way they did before from all sides?"

"I'll handle that," Bill said. He knew he didn't have a chance if they started working their way toward him under the cover of darkness. If they charged mounted, he could stand them off for a time. But if they crept in on him, they could get close enough to use their deadly yataghans.

He believed Sandy could get through if he once got astride the superb white horse that was only fifty feet away. Those fifty feet would tell the story. The kid would either get through safely or be killed in the saddle-which was better than being tortured.

Bill closed his lips tightly and peered through the telescope again. "All right, kid," he said. "Good luck! Shoot your way through if you have to. Don't let them take you alive."

He found Sandy's hand with his own in the dark.

"I hate to leave you here, Bill," Sandy said anxiously.

"Don't worry about me, kid." Bill laughed. "None of those desert lice have my name on their bullets." ''I'II be seein' you, Bill." "Right, kid. Go like the devil when you get aboard."

He saw Sandy drop over the side of the Lancer, saw his dim form, bent half double, flash across that fifty feet of sand. He expected to hear a fusillade of rifle shots and see him pitch forward on his face at any moment. Those few seconds brought cold perspiration out on Bill's body and left him wear and trembling. He saw the white horse go up on its hind legs with its front ones pawing the air. He saw Sandy bent over its neck. For all instant they were silhouetted against the sky, a perfect target for enemy bullets.

Then the horse and Sandy became a part of the desert night. He saw them again for an instant as Sandy topped the first hillock, saw them plunge out of sight on the other side.

Shouts and rifle shots floated back to his ears. Then a bedlam of clamor, Arab oaths, and he heard an automatic spit many times - and knew that Sandy was still in his saddle.

As the shots and cries died in the distance, Bill knew that Sandy had got away without being hit.

He leaped for the telescope and then clamped his fingers down on the trigger cables of his two .50-caliber guns as twenty or thirty men came charging over the crest of sand ahead, on foot. His bullets cut two paths through their ranks before they plunged down the side and were out of range. He dived into the rear cockpit of the Lancer and swung the .30-caliber gun to bear on the screaming tribesmen as they came on and on.

His blood ran cold as turbaned heads appeared above the rim of the Lancer. The two automatics in his hands were hot as he fired them point-blank into the desperate, mad faces. Something seared his arm as a dagger slashed through his overall.

WHEN young Sandy went over the side of the Lancer he was not worried about Arab bullets. He was worried about one thing only. That was whether he could get into the saddle of that white horse and stay there. He would rather have been shot than to be thrown from the horse's back under Bill's eyes.

He approached the horse with the easy, cautious movements of a true horseman. He spoke soft words to him, words that had no meaning other than to quiet the nerves of the trembling horse. He ran an eye over the snow-white shoulders and hind quarters of the superb creature and thrilled as the horse nuzzled its muzzle into his hand.

Then his foot was in the left stirrup and he swung himself into the saddle. For an instant the horse came up on its hind legs, pawing the air.

Sandy leaned over its neck, calling soft words into its ear. Its forelegs I came down; Sandy pressed his knees into its ribs and kicked gently on its flanks.

Sandy learned then why old Arab, I poets sang songs to their horses. The horse took him over that first hillock with breathless speed. He saw five or ten unmounted Arabs only a few feet away from him. He cut the first one down with his automatic as he raised his rifle to his shoulder. Then he emptied his clip, swung the horse to the right, leaned low over its withers and cried in its ear.

The horse settled down to the task before him with long, swift strides that took Sandy out of sight behind the first hillock before the Arabs could mount their horses. Bullets sang by his ears and kicked up the sand around him. But none of them touched him.

The Arabs who followed him never came close enough to get an effective shot at him after that. His horse took him over the desert sand with the speed or a greyhound and the endurance of a camel.

"Good gosh," Sandy said to himself, "I'm going to take this horse home with me if it costs every cent I can beg and borrow;"

He was worried by the pursuing Arabs, and he was worried about Bill's safety. But he wasn't enough worried to keep him from thinking about a name for the horse and the horse's performance.

Sandy didn't try to stop the racing beast as the guard at the gates of the air field threw a challenge at him. He couldn't have stopped him if he I had tried.

But he managed to bring him to a halt before the officers' quarters, where he believed he would find Kestrel and Shorty. He brought him up on his haunches, cleared the saddle in one bound, and raced through the doors.

Again he paid no attention to the challenge of the guards as he pounded on the door of Kestrel's rooms. When the door flew open to expose the haggard face of the wing commander, Sandy half-staggered, half fell into the room.

"Where - where," he grasped, "is Shorty?"

"Searching for Barnes," Kestrel snapped. "How did you get here? Where is Barnes? We've scoured the countryside looking for you. I called my men in at dusk, but Hassfurther is still out. He thinks you must have crashed in the mountains around Petra."

"I've got to get Shorty on the radio from my Snorter," Sandy said. "'We were attacked by the stolen Royal Air Force planes. We shot four of them down, then ran out of fuel. The two that escaped came back to get us, but we drove them off.

" After dark we were attacked by desert tribesmen. We held them off and I captured a horse and rode to Ma'-an. Bill is still out there. I've got to find Shorty. I---" Sandy stopped, gasping.

"I'll order: a squadron of my men out immediately," Kestrel snapped. "Was there any danger of another attack on Barnes?"

"He's probably dead now," Sandy said. "I don't see why you couldn't find us. We were down only about twenty miles from Ma'an."

"We went northwest, over the Syrian Desert," Kestrel said, "That was the direction where you were last seen. We didn't worry about you until nearly sun down. Hassfurther thought he ought to stay here until he knew about Gleason."

"What about Gleason?" Sandy barked.

"He's all right," Kestrel answered. "He'll pull through in no time. He has a constitution like a horse."

" An Arab horse," Sandy said, and bounded to his feet. "Bill doesn't want you to send your men out. Shorty and I can get him. We'll take him fuel. Your men are apt to crack up their ships trying to sit down on the irregular sand hillocks."

"Nonsense!" Kestrel barked.

"If you want to do anything," Sandy said as he started toward the door, "take care of my horse!"

Three minutes later he made contact with Shorty by radiophone.

"Listen, Shorty," he said; "Bill is down about twenty miles from Ma’an. He was surrounded by desert Bedouins, armed to the teeth, when I captured a horse and managed to get to Ma'an."

"What's his position?" Shorty snapped.

Sandy gave it to him.

"All right kid, I’m going there now. You load some fuel into your Snorter and follow me. You say he’ll have his landing lights showing?"

"That's right, Shorty. Be careful going in. Drop a flare. It's a tough place to land. You'd better go in a little away from him, because there are dead horses and men all around the Lancer."

"Right, kid. Hurry! I'm signing off."

With the help of a dozen grease monkeys, Sandy loaded enough fuel into the rear cockpit or his Snorter to bring the Lancer back.

He whipped the Snorter into the air with a characteristic touch and stuck the nose almost due west. He picked up the landing lights of Bill's Lancer and Shorty's Stormer within a few minutes.

His heart was pounding so hard that he could hardly breathe as he dropped a flare and set his Snorter down within fifty feet of Shorty's. He was half afraid to climb over the side of the Snorter. Afraid of what he might find. He knew that only a miracle could have saved Bill from that band of fanatics surrounding him.

Yet his absolute faith in Bill told him that Bill was alive - that he had managed in some manner to survive the rifles and daggers of the fierce tribesmen.

He dropped over the side of the Snorter and started running through the desert sand. When he was halfway to the Lancer he came across the bodies of a dozen dead Bedouins. They were piled on the rim of a hillock where Bill's bullets had found them as they came over the top. When he could restrain himself no longer he shouted Shorty's name. Then again, and again.

His blood seemed to freeze in his body as no answering call came back to him - only the faint sighing of the desert winds and the swish of the sand beneath his feet.

He drew his automatic from an overall pocket and slowed his pace. Had they got Shorty, too? Were they waiting for him? Cold chills crept up his spine and seemed to fasten around his heart.

Then the sound of faint voices came to his ears. He stopped and stood motionless. The voices came again, higher, clearer.

He recognized the voice of Bill Barnes. He shouted again. And this time Bill's voice came back to him. Sandy covered that remaining space to the Lancer with pounding feet and heart. He swung up on a step of the Lancer and pulled himself up.

Shorty was bending over Bill, applying antiseptics to a half dozen minor wounds. Sandy's face blazed with anger as Shorty and Bill gazed up at him with the bland expressions of men who are used to such things.

"My gosh!" Sandy said. "Why didn't you answer me? I thought you were both dead! I was expecting to have my throat cut any minute."

"Tom Mix himself." Shorty chuckled. "Where's your horse, cowboy?"

Bill laughed. "We heard you and thought that you'd get over here all right," he said. "We didn't hear you shout."

"You're all right, Bill?"

"Just a few dagger scratches," Bill said. "They tried to get me again, and almost succeeded. I cracked a few heads and threw a tear bomb at them. It took the fight out of 'em. They went streaming back across the desert - what was left of 'em - to the place they came from."

BILL BARNES could hardly hold his eyes open as he sat in Kestrel's quarters a half hour later.

"Gleason's all right, you say?" he asked.

"Quite," Kestrel answered. "McCardell says he has a splendid constitution. He'll be as good as new in no time."

"It's too bad I ran out of fuel," Bill said bitterly. "I could have picked up the man who bailed out of his ship and brought him back here. We might have made him talk. I'm sorry I had to shoot down four of your stolen ships, Kestrel. But that leaves your enemy with only four. He can't get very far with them."

"You're wrong, Barnes," Kestrel said wearily. "Ten more of our ships were stolen from under our noses today. It must have been part of that group that attacked you."

Bill stared at Kestrel incredulously.

"Ten more!" Bill gasped. "How could they do it? Who flew them?"

"Let me explain," Kestrel said, mopping his face with a shaking hand. "I understand now why Douglas was framed and then murdered. And why the attack was made on you. Douglas was one of the three flight commanders in the squadron whose planes have disappeared. The other two were named MacTavish and Sneed. They are the two scoundrels who have been working for the enemy inside our lines. They disappeared along with the captain appointed in Douglas' place to-day."

Bill Barnes got to his feet and paced across the room. When he whirled, he addressed Shorty Hassfurther. "Do you get the set-up?" he asked. .

Shorty stared at him for a moment, then slowly shook his head. "It's coming to me," he said.

"MacTavish and Sneed tried to get Douglas to work with them," Kestrel went on. "He wouldn't listen to them. So they framed him as a common thief so he would be cashiered and out of the way, and another man put in his place who would work with them. They slipped in a bunch of renegade fliers; there are plenty of them out here in the East. They did it right under our very noses. They dressed them in British uniforms and waited for the right time to strike. Our enlisted mechanics took their orders from MacTavish and Sneed. They didn't know there was anything amiss until it was too late.

"Douglas must have found out something. That's why he stayed around here. They learned that he was getting on the right track. And--"

"They murdered him!" Shorty said bitterly.

"That's it!" Bill snapped. "But what about the squadron commander? Have you checked on him?"

"I'm doing that now," Kestrel said wearily.

"Don't you have some idea who is behind all this?" Bill asked. "Hasn't some native sheik or former ruler made trouble for you?"

"Plenty of them," Kestrel said. "The French have had the same trouble in Syria. The Arabs have been dreaming of one great Arab State for hundreds of years. An Arab State ruled by Arabs, without a mandate."

"But where," Bill asked with as much patience as he could muster, "are their headquarters? Where can they hide those planes right under your nose?"

" And just who disgraced and then murdered Douglas?" Shorty snapped.

Kestrel groaned as they threw the questions at him. He was in the last throes of despair. His bronzed face was white and haggard; his hands shook as he poured himself a drink and downed it in one gulp.

"Gentlemen," he said, "I would give my life to be able to answer those questions. And I've got to find the answer soon or Trans-Jordan is going to flow deep with human blood.

"Whoever is the leader of this rebellion is working with sagacity and craft. Usually different tribes of Arabs will not band together - not even against a common enemy. They prefer to go their own way, fighting their own battles. But, now they are being cleverly welded together, if I can believe the reports that are coming to me from our intelligence units. They are ready to strike in unison when they receive the word. When they do, the slaughter will be frightful.

"The desert tribesmen are mad fanatics when they go into action. They lose all control of themselves. Their only desire is to murder, torture, and plunder. They have always believed that the desert belongs to them. That is why they prey on caravans and pilgrimages to Mecca. They believe they are justified in murdering and plundering. They would delight in cutting all of our throats.

"That is why I would advise you to go on to Cairo or Alexandria as soon as you can move Gleason. You will be safe there. You ---"

"We’II stay here," Bill said decisively. "We're sticking. You asked for our aid before. Now you're going to get it. Remember, Douglas has been killed and one of my men dangerously wounded. That's reason enough for me to see the thing through.

"But now," Bill went on, "I've got to have some sleep. I can't go on until I've had a few hours rest. You'll let me know if anything develops with Gleason?"

"I'll let you know ," Kestrel said.

Shorty followed Bill from the room.

SHORTY HASSFURTHER strode across the landing field at Ma’an shortly after breakfast the next morning. His face was like a thundercloud.

Bill had told young Sandy to stand by where he could find him - and Sandy had disappeared. Shorty had an idea where he could find him, and why. He swung along a string of buildings at the edge of the field. These were the stables.

In a small corral between two of the buildings he came upon Sandy. He stopped abruptly as he heard a string of words coming from Sandy's lips, and his scowl changed to a grin. He saw that Sandy was talking to the horse he had ridden into Ma'an the night before, and he saw that he was deadly serious about it. He was making emphatic gestures as he recited poetry to the horse. Shorty stifled his laughter and listened.

--- "Away! the fevered dream is o'er,

I could not live a day, and know

that we should meet no more!

Who said that I would give thee up?

Who said that thou wast sold?

'Tis false -- 'tis false, my Arab steed!

I fling them back their gold!

Thus, thus, I leap upon thy back,

and scour the distant plains!

Away! Who overtakes us now shall

claim thee for his pains!"

With the last words Sandy fastened his hand in the horse's mane and started to swing himself to its back. But Sandy's movements were too quick. They frightened the horse and he went shooting to one side and came down with his legs stiff. At the same instant Sandy went shooting in the other direction and came down on the back of his neck.

Shorty could restrain his laughter no longer. He threw back his head and howled with glee.

"You gave him too much juice when you tried to get off the ground, kid," he shouted. "You want to be careful or you'll rip out your undercarriage."

Sandy rolled over on his stomach and looked at the horse, then at Shorty. His face was red and his eyes were spitting fire.

"You hit him with something," he said to Shorty.

''I didn't hit him with anything," Shorty denied. "He just doesn't recognize you. You aren't wearing one of those head cloths and mantle." Shorty's face was grave now. "You've got to dress like an Arab if you expect to ride Arabian horses," he went on.

"They're funny that way. I read an article about it once. They won't let ally one ride them if he doesn't wear a head cloth."

Sandy studied Shorty's face suspiciously as he climbed to his feet. "You sure about that, Shorty?" he asked.

" Absolutely, kid," Shorty said solemnly. "You want to get one of those gay headdresses and a silk cloak with a leather girdle around it, and a dagger in the belt. Then your horse will eat out of your hand!'

"I wonder," Sandy said, "where a fellow could buy them?"

"Oh, almost any place," Shorty answered. "But right now Bill wants you. We're going over to Douglas' rooms to take a look around, and he wants you along."

"0.K., Shorty. I'll be right over. I can get the cloak and head cloth when we get back."

"Yeah. But don't forget it," Shorty said earnestly. "You can't expect to ride one these horses without 'em."

Sandy looked at Shorty out of the corners of his eyes again. He was almost sure that Shorty wasn't kidding him. But he wasn't positive. He had had too many such experiences with Shorty in the past to be certain.

"Say, Shorty," he said suddenly, "how do you suppose I can get this horse back to Barnes Field? It's just the horse I've always wanted."

"We'll take care of that when we come to it," Shorty answered, trying to suppress a grin. "Don't worry, we'll find a way."

BILL, Shorty, Sandy and Wing Commander Kestrel spent an hour going over the things in Douglas' room, trying to find some clue to the secret that had been in Douglas' possession.

While they were there, messengers came constantly with dispatches and reports for Kestrel. With each one his expression became more glum and desperate. Finally he blew up.

"I can't see that this is getting us any place. While we poke around here the natives are getting ready to fall on our necks," he said.

"Sandy and I will look around here a bit longer," Bill said. "Shorty, you go back with Kestrel and see how Red is coming along."

Kestrel hesitated, but in a moment he took his leave, followed by Shorty.

When they were gone, Bill turned to Sandy. "Douglas' servant has been hanging around trying to tell me something with his eyes. He was afraid of Kestrel. He's outside the door, I think. Call him in."

Sandy went 9ut the door and came back in a few minutes with a man who was both frightened and inarticulate. Bill spoke to him both kindly and sternly. The man shook his head and began to jabber in Arabic:

"Take it easy," Bill said. "Can you speak any English?"

"Few words," the servant answered. "You want to tell us something?" Bill asked slowly, enunciating each word carefully.

"Me," the man said. "servant." He crossed the room and pointed to a picture of Douglas. "Name, Jezzar."

'"Jezzar," Bill said, smiling. He studied the man's face and tried to gain his confidence by his expression. "You tell me?"

"I know," Jezzar said, and burst into Arabic, his nervous, slender hands fluttering before his face, his eyes shifting about the room.

Bill held up a hand. '"Take it easy," he said. '"Tell me in English."

"To-night," Jezzar said. '"I take you. Petra. Es Siq, when" He made motions with his hands.

"He means when the moon is up!" Sandy said brightly.

"At dark?" Bill asked.

"Dark. Es Siq," Jezzar said, "Ride horse?"

"Tell him," Sandy said, "we can ride any horse in Arabia."

"Shut up!" Bill said to him. "Douglas - Petra?"

Jezzar nodded his head. "I show you," he said. Then he touched his finger to his lips and glided toward the door.

Bill Barnes stood without speaking for a period of several minutes. He was thinking about the slaughter that had occurred in Es Siq a few nights before. He was wondering if the man was to be trusted. At least, they would have to gamble to find out. He counted on the fact that there had been genuine distress and sorrow in the man's eyes when he had pointed to the picture of his dead master .

" All right, kid," Bill said to Sandy. "That's your job - get me a horse to ride. We'll meet him in Es Siq at dusk."

"What," Sandy asked; "do you suppose he is going to show us?"

"Your guess is as good as mine," Bill answered.

THE DARK, narrow gorge of the Wadi Musa was as silent as a tomb when Bill and Sandy rode into it at dusk that night. The only light that came to them on the dangerous path was a streak of silver moonlight far overhead.

"This," Bill said, "'would be a swell place for an ambush."

" "It's spooky, Bill," Sandy answered. "It is filled with the ghosts of dead men."

They both felt their hearts crawl up into their mouths as a white figure on a white horse loomed up in the darkness ahead, BiIl’s automatic leaped into his hand as he called out softly, "Who is there?"

"Jezzar," came back to them as softly. "Follow."

He swung his horse around and led them deeper and deeper into the black chasm.

"Have gun ready," he said once, dropping back beside them.

The soft sighing of the night wind, heavy with the scent of oleanders, the creaking of their saddles and the scrunch of their horses' feet on the pebbles of the trail, were the only sounds to break the heavy silence.

As they came out of the mouth of Es Siq, a clearing spread out before them and their first glimpse of El Khazna, in the moonlight, was as unreal as the figment of a dream.

The nine figures carved into the front of the upper story of the temple to an unknown god took on fantastic shapes in the shadows - shapes that seemed menacing and fearful in the absolute silence of the night.

Sandy's breath whistled in his throat as he realized that the slithering shadows that crept along the face were not shadows. They were lizards, iguanas and snakes.

Jezzar, riding on ahead of them, called upon Allah to uphold his horse as it stumbled, then broke into a soft song. To the south a mountain rose out of the valley floor to the great high place of sacrifice.

The dim outline of the Roman amphitheater took shape as they passed out of the Outer Siq, and beyond the ruins of the Palace of the Maiden, grotesque in the moonlight.

To the west rose the dim shape of Jebel ed Der, the Mountain of the Monastery. To the north the top of Jebel Harun, where lights flickered around the tomb of Aaron, the Moslem shrine holding the sacred Dushara.

As Jezzar dropped back beside them once more, he touched his lips with his fingers and' ran them across his throat; they knew only too well what he was trying to convey to them. He pointed to the mosque where lights burned, and waved his hand from left to right to signify that there were thousands of men on the mountains around Petra.

Farther on they entered the gorge of Es Siyagh and crept along the base of El Habis, the unfinished tombs of the ancient Edomites. Dark splotches on its sides were sepulchers, and on the top, gleaming dark in the moonlight, were the ruins: of a castle.

Beyond El Habis loomed Umm el Biyara, dark and silent and menacing. As Jezzar brought his horse to a halt and pointed a finger toward the ancient stronghold, Sandy's horse came up on its haunches, then plunged toward the great wall of stone that was the base of Umm el Biyara.

"Whoa, you fool!" Sandy shouted as he tried to swing his mount around. But for the moment the horse had the bit between his teeth and showed no inclination to turn around. Then, as the bit cut into its tender mouth it came up on its haunches again and whirled.

As its front feet touched the ground, Sandy described an arc over its head. He struck the ground feet first, and managed to hang on to the reins.

That somersault over the horse's head was all that kept Sandy from being annihilated by that first blast of rifle fire from along the base of Umm el Biyara. The bullets tore over his head and came to a stop in the body of Jezzar, just behind him. One strangling cry came from the lips of Douglas' old servant. Then he rocked backward and rolled off his horse like a bag of meal being dropped from a wagon.

Sharp stabs of orange flame appeared from a dozen places along the base of the ancient stronghold as Bill came charging in on his horse and grabbed at Sandy's reins.

"Mount, kid!" he shouted. "They got Jezzar. He was dead before he hit the ground."

"Hold him, Bill," Sandy panted. He circled to the left {)f the plunging horse and got one foot in a stirrup. As Bill let go of the reins and emptied his automatic toward the stabs of orange flame, Sandy managed to swing into the saddle.

"Come on!" Bill shouted. "We've got to get out of here the best way we can. I memorized the map Kestrel gave me. We'll follow through the ruins of Petra along the ancient wall to the Outer Siq. I can see white forms coming out of the darkness over there. They'll get us in a few minutes. Are you all right?"

"I'm all right, Bill," Sandy puffed, "if I can make this fool horse behave. He wants to go toward that gunfire."

Bill swung his horse over beside Sandy and grabbed at his reins.

"I thought you could ride any horse in Arabia," Bill grunted as he rode through the ruins, leading Sandy's horse.

"He went nuts, Bill," Sandy said. "I can manage him now. I'll follow right behind you. We'll make better time."

"We'll have to," Bill growled. "If they can signal ahead they'll cut us off in Es Siq and we won't have a chance. We've got to keep ahead of them."

The sharply turning trail that wound between the sandstone walls of Es Siq was the thing that kept them from being slaughtered by the hard-riding Arabs behind them. Their escape became a running fight that lasted throughout that long mile from the ruins of the city to Bab es Siq.

There they reloaded their automatics, took a prone position behind the crumbling gates and fired at random as they heard their pursuers drawing close. In another thirty seconds they were again in their saddles and racing across the desert sand toward the airport at Ma'an.

"Did you have any idea where Jezzar was taking us?" Sandy asked as they swung out of their saddles before the officers' quarters on the airport.

"None," Bill said shortly. "He was about to tell us something when they opened up with their rifle fire. The natives probably have guards all through the city to protect the Dushara. They shoot first and ask questions afterward."

"You know, Bill, " Sandy said cryptically. "I have a hunch. I---"

"Get yourself some sleep," Bill said gruffly. "That's what you need most. I'II have to make a report to Kestrel."

"But listen, Bill!" Sandy said. "I think---"

"Good night," Bill said, and started toward his quarters.

IT WAS shortly after dawn the next morning when Sandy stole over to the stables and asked a native groom to saddle his horse.

A few minutes later he was in the saddle and leaning over the neck of his mount, whispering in its ears the way he had seen Western riders do in the movies.

"We'll show 'em, old pal," Sandy said in the horse's ear. "We'll teach 'em to pay some attention to our hunches."

The white horse turned its head and eyed Sandy with anything but a friendly look, and Sandy remembered what Shorty had told him. He had forgotten to wear a head cloth and mantle. And he could see that his horse didn't like it.

''I'II remember before we come out again," Sandy told him as they made their way over that boulder-strewn waste of sand between Ma'an and Bab es Siq.

The sun was playing a symphony on the red walls of Es Siq as Sandy guided the dainty-stepping steed through the winding pass. As Es Siq ended abruptly into a cross gorge that was the Outer Siq, the face of El Khazna gleamed like white marble ahead.

As they stole past the old Roman theater, Sandy checked the ammunition in his automatics and in his extra clips. His heart was pounding now, and he could feel his face burning with excitement.

Taking a westerly course along what was once the main avenue, he passed the remains of triple triumphal arch from the Roman period. Along the sides of the city were the ruins of hundreds of temples cut into the sides of the stupendous cliffs; its courts, libation basins, and altars where the ancients worshiped all carved from rocks of ocher and all shades of red.

Sandy gazed with silent awe at the crumbling tombs, temples and palaces built oil the towering limestone hills above the city. Then his breath quickened as he sighted the ruins of the Crusader castle atop El Habis, and behind it the great flat rock that was Umm el Biyara.

He guided his horse to the place where he believed Jezzar had been murdered the night before. But there was no sign of his body or his horse.

It was there that Sandy let the reins fall loosely on the Arab horse's neck. The horse raised its head and peered toward the great mountain of stone, then whinnied softly and moved toward it without guidance.

"That's the old pal," Sandy whispered. But he didn't touch the reins. He let the horse have its head and almost held his breath as the horse advanced.

Picking its way carefully and surely, the horse cut around a rough ledge of overhanging rock, went down the side of a ravine and up the other side. At the top it entered what looked like a stone doorway, barely high enough to admit the horse and Sandy on its back.

In a moment the horse came out on a narrow pathway, wide enough to pass along, clinging to the inside. As they came out into the air again Sandy's red face suddenly became white. He saw that they were already fifty or sixty feet above the jagged rocks at the base of the stone mountain. There was not room for the horse to turn around on the rock-cut couloir. If its feet slipped they would both be plunged to their death on the rocks below.

If they went on, Sandy believed, the horse would take him to the secret stronghold of the men who had attacked them in the air and on the ground two days before.

For an instant Sandy hesitated. He checked his horse until he came to a halt. Then he clenched his teeth, took one of his automatics out of its holster and said aloud, " All right, baby. Let's go!"

BILL BARNES tried to blink the sleep out of his eyes as he slapped his bare feet down on the floor of his room. He stared at Shorty Hassfurther and saw that he was dressed for flying.

"Say that again," he said to Shorty. "One of the grooms at the stables told me Sandy had his Arabian steed, as he calls him, saddled at dawn. He left here alone, headed for Petra."

"The nit-wit!" Bill growled as he reached for his clothes. "He tried to tell me last night when he got back about a hunch. I wouldn't listen. He's going to play it alone."

"What is he going to do?" Shorty asked.

"I wish I knew," Bill snapped. "Listen, Shorty. Get the Lancer and your Stormer warmed up. We'll have to go out and look for him if he hasn't had his throat cut already."

"There's hell popping this morning," Shorty said. "I just talked to Kestrel. Rioting in several cities in Trans-Jordan and Palestine. It's only a question of time, he says."

"Yeah," Bill growled, "and that fool kid has to go out and stick his head right into the noose. I think I know what he had in mind. We'll fly over Petra first. Come on, let's go!"

"I'll have the Lancer ready when you're dressed," Shorty said as he jumped for the door.

"Check the ammunition counters!" Bill shouted after him.

Twenty minutes later they were above the jagged, dazzlingly colorful twin ranges between which the city of Petra lies. They sped down the length of Es Siq at an altitude of only a few hundred feet. Above the Wadi es Siyagh they darted through wisps of clouds until they were near the peak of Jebel Harun. They circled the white dome of the tomb of Aaroff and felt rifle bullets drumming into their wings.

As they swung back over the valley of Petra, Bill flipped his radio switch, "Get down a couple of hundred feet," he said to Shorty. "We'll see him now if we're ever going to see him."

He kicked the rudders of the Lancer and stuck the nose down as the flat top of Umm el Biyara took shape to his right. He flew only a hundred feet above it while he studied every detail.

Suddenly his hand tightened on the control column and his face became a shade whiter. Below him he saw a lone figure riding on a white horse. He knew it was Sandy. He shouted into his microphone to Shorty and pointed as a swarm of brown-faced men dressed in the gaudy mantle of the desert Bedouin appeared from nowhere above Sandy.

For one horrible moment Bill saw Sandy's horse rear up and swing its front feet toward the edge of the narrow little path it had been climbing. Then one of the mantle-clad Arabs had it by the bridle. He saw Sandy try to bring his automatic into play while he tried to gain control of the horse. Then he saw the barrel of a rifle crack down on Sandy's head and saw him topple from the saddle.

Bill brought the Lancer around and stuck the nose down toward that little knot of men as they carried the unconscious Sandy toward the mouth of a cave. But he didn't dare clamp down on his gun trips. He cursed between clenched teeth as he zoomed upward and saw the Arabs disappear. He tried to find the path Sandy's horse had been climbing, but it had disappeared. Without some moving object on which the eye could focus the path could not be seen.

Bill knew now that he had been right about Sandy's hunch. Sandy had taken his horse back to the spot where it had balked the night before, when it had tried to go toward the base of Umm le Biyara. The horse had led Sandy to the secret entrance to the top of Umm el Biyara.

But where, Bill asked himself, were the people who were inhabiting the ancient stronghold? How could they hide themselves so completely from sight?

He became aware of Shorty's excited voice in his ear. He said, "I didn't get what you said, Shorty. I'm trying to figure how we can get in there to get Sandy out."

"That is where those stolen ships are being concealed," Shorty said. "They must have a hangar under the surface with a camouflaged top that makes it look like the regular terrain. It's the only place for them to be. They could land those little fighters on the top."

"You're right, fella!" Bill yelled. "Douglas must have learned about it or suspected it, and they killed him to keep their secret until they are ready to strike."

"Kestrel says they're ready now, Bill," Shorty said quickly.

But Bill wasn't listening to him. He was talking to the radio man on the field at Ma'an.

"I've given the word to Kestrel," Bill said in a moment. "He'll send bombers to help us bomb them out. But we've got to get Sandy out of there before they begin to blow it apart. I'm going to sit the Lancer down on top of the place if I can make it. I think I can. What do you say, fella? Are you coming in after me? It's not an order. Use your own judgment."

"I'll be on your tail, Bill," Shorty answered. "Perhaps you'd better drop a couple of bombs yourself to soften 'em up."

"Let's go!" Bill roared.

He kicked the Lancer around and stuck the nose down as he unfolded his retractable landing gear. He set his flaps well down and cut his engines, but he was still doing a hundred miles an hour as he skimmed the surface of the great flat rock with his landing wheels. At the far end, when it seemed that nothing in the world could keep him from plunging over the side, he kicked his rudders and swung the big ship around.

Shorty fish-tailed in a few feet behind him and brought the slower-Ianding Snorter to an abrupt halt.

"Sit tight for a moment until we see what happens," Bill said into his microphone.

They didn't have long to wait. The whole top of the stone plateau suddenly swarmed with men. They popped up along one edge and came storming up like a regiment of Sikhs going over the top, their robes streaming out behind them, their faces contorted with hate.

"Swing your ship around and let 'em have it!" Bill shouted into the microphone. At the same time he fastened his fingers down on his own 50-caliber guns. His two fixed guns stuttered out their song of death, to be joined a moment later by the louder roar of his cannon.

But his guns were set too high. His bullets ripped harmlessly over the heads of the charging mob of madmen.

"Bill!" Shorty's voice called in his earphones. "They're bringing up one-inch rapid-firers and machine guns. They'll tear us to pieces!"

"0.K., guy," Bill said, and now his voice was calm and steady. "Give your ship the gun. Take a run the length of the top and then give her all she's got when you strike the edge. It's our only chance. We'll have to bomb them out."

How Bill and Shorty ever got through that frightful hail of lead no one will ever know. The charging tribesmen broke before the scream of their propellers and the roar of their engines as Bill and Shorty headed their ships into their midst. But when they broke they I dropped to their knees and emptied their rifles into the fleeing ships. From the edge of the plateau came the death rattle of a dozen machine guns and the louder bark of one-inch rifles.

The speed of their ships was the only thing that kept Bill and Shorty from being annihilated before they reached the edge of the plateau. They could feel bullets drumming into the skin of their ships and could feel them trembling like mortally stricken animals under the impact.

But they made the edge, with a prayer on their lips that when they went over the edge their motors would be functioning.

For one awful second the two ships sagged, then the noses settled, the tails lifted, and they began to climb.

"Are you 0.K., fella?" Bill asked, Shorty.

"O.K., Bill," Shorty answered, "but my ship is a sieve."

"Get some altitude," Bill instructed.

"What about Sandy?" Shorty asked.

"We'll get him," Bill said grimly. "If they hurt that kid I'll---" He stopped. His bronzed face was white and strained as he gazed over the side of the Lancer. As his eyes fastened on the top of Umm el Biyara he gasped.

A dozen of those fast single-seaters belonging to the Royal Air Force were standing in a line on the far end of Umm el Biyara. Their props were turning over, and they were facing into the wind. Men were climbing over the sides into the cockpits.

"They're coming after us, Shorty," Bill said, and there was a ring of real anticipation in his voice.

"Good!" Shorty Said. He leaned over the side of the Snorter as the first of the little ships whipped into the air, followed by another and another.

"Stay up where you are," Bill instructed. "Kestrel will send some bombers. He can break up this uprising before it gets really started."

Bill whirled the master tuning control on his radio panel and chanted the call letters of the Ma'an airport into his microphone again. Suddenly he was aware that Shorty was flying in close to him, trying to signal with his arms and plane because his radio wave length had been tuned out. Bill twirled the wave-length control and barked Shorty's name.

"Look down below, Bill!" Shorty gasped: "They have Sandy spread eagled out on the top of Umm el Biyara. They must have tuned in our wave length and heard you say you were going to send for bombers. That's their answer."

Bill's heart climbed up into his mouth as he grabbed at a pair of glasses and turned them on the figure stretched out on the ground five thousand feet below. He turned the glasses directly on Sandy's tortured face. Then he took them away as his stomach turned over from horror.

In that one glimpse he had seen that Sandy's face and head were battered and bloody. His arms and legs were spread out and pegged to the ground. His face was a twisted blotch of agony.

Cold perspiration popped out on Bill's face and his hand gripped the control column so tightly it seemed he might rip it from its socket.

" All right, Shorty," he said, trying to keep his voice steady. "Those twelve single-seaters are above us now. They're in four V formations of three planes each. They're swinging back to attack. Remember what they did to Douglas!"

"I'll remember!" Shorty snarled, "We've got to get to Sandy, Bill!"

"We'll get him!" Bill said, so quietly Shorty could hardly hear the words.

AS the twelve British ships completed their turn they broke the four V formations and formed two stepped-up columns of six planes in a line, each a little above and behind the one in front. Bill saw the leader rock his wings and knew the instant they were going to dive. He spoke into his microphone softly.

"The column on the left is yours," he said to Shorty. "When they’re five hundred feet away, dive under 'em and then chandelle back to get on their tails. Give 'em hell, fella!"

"Give ‘em hell!" Shorty echoed. "One for Douglas, one for Red, and one for Sandy!"

Bill eased the control column back and sent the Lancer up into an abrupt climbing turn until it almost stalled; then he whipped the nose level and down again. For an instant he pushed his throttles all the way open. A gale whined and snarled over the cantilever wings and streamlined body of the Lancer as the silver plane plunged toward the stepped-up column of single-seaters below it.

Bill's fingers clamped down on his gun trips when he was only two hundred feet above and behind that straight column. His bullets tore into the last ship as it came under his telescopic sight. They drew a pencil line down the center of the fuselage until they reached the open cockpit. There they drove into the head of the man whose hand was wrapped around the controls.

He died before he knew what manner of thing had hit him. His ship skidded off to the left and stuck its nose downward. It dived into the earth with its wings folded back, like a gannet diving for a fish.

The next man in line threw one desperate look back over his shoulder and sideslipped his ship out of the way of Bill's deadly fire.

Bill caught the third one from the rear with his .37-mm cannon as he started a barrel roll. A great cloud of black smoke and orange flame took the place of the one-seater as the shells detonated on the engine block. Debris flew in a hundred different directions. There was no indication that a man had been at the controls as the smoke cleared away. He had become a part of the scattered debris.

The three leading ships in the column peeled off in three different directions. Bill saw one of the biplanes whirling toward the earth like a falling leaf as Shorty riddled it with bullets. Then he zoomed the Lancer up underneath one of the three ships that had broken formation.

For a split fraction of a second the lean fuselage came under his sights. His fingers clamped down on the triggers in the stick. His powerful .50-caliber bullet ripped the bottom out of the rugged little fighter. The pilot shot up in his seat as the bullets drove through his body. His arms sprawled over the cowling as the doomed ship fell into a spin.

"They asked for it!" Bill said to himself viciously. There was no mercy in his heart now. He knew these men had murder in their hearts. They had tried to live by violence, and they must die by violence.

He saw that the five remaining planes of the column Shorty had singled out they were forming a Lufberry circle around him. They were trying to tighten it up to get Shorty within the vortex of their concentrated fire. He smiled grimly as he saw Shorty whip his Snorter directly into the guns of one of them. But Shorty's bullets were writing death across the face of the enemy pilot before he could clamp down on his triggers. The plane fluttered out of the fight toward the earth below.

Bill kicked the Lancer around and picked off another of the four ships circling Shorty. He saw Shorty's hand come over his head with his thumbs sticking up.

Within a space of three minutes time they had shot six of the one-seaters out of the air. The other six were forming in two V formations of three each now. The leader was giving orders with tail wags and hand signals. They were spiraling up, seeming reluctant to return to the attack.

For an instant Bill studied the leader while he flipped his radio key. Then his gaze whipped toward the direction of Ma'an as the drone of twin-motored bombers came to his ears.

His face froze as he saw a route column of six giant bombers speeding toward him. Above the bombers was a squadron of eighteen British planes, identical to the ships he and Shorty had been fighting.

"Shorty!" he screamed into his microphone. "I'm going to land on Umm el Biyara again. You'll have to clear the way for me. Those bombers will go to work on the place. They don't know Sandy is spread-eagled out on the top. Attack those machine guns and ground guns while I land and get him!"

"You'll never get down, Bill!" Shorty shouted. "You can't use your guns. They'll tear you apart!"

"You'll have to hold them off," Bill said. "Rake the south side with your guns. Get down to fifty feet. It's our only chance. Here I go! Get on my tail!"

Bill sat the Lancer down on the top of Umm el Biyara again in the face of that deadly concentrated fire. But it did not last for long.

Flying almost in the mouth of the machine guns on the ground, Shorty tore their crews to ribbons. Dead men piled up at the mouths of the entrances to the underground caverns. He stilled every gun while Bill brought his ship around and rolled across the plateau toward sandy.

Then he was over the side in two jumps, tearing at the pegs that held the helpless Sandy.

"You all right, kid?" he asked, his breath coming in quick gasps.

"Just a little dented around the edges, Bill." Sandy managed to grin. "They – they --" His eyes closed as his head lolled back, and Bill knew that he had fainted.

Bill struggled desperately as he saw the big bombers nosing down to drop their horrible eggs. Then he had Sandy over his shoulder. He struggled up the side of the Lancer and dropped Sandy in the rear cockpit.

Half the world exploded beyond the far rim of Umm el Biyara as he gave the engines of the Lancer the gun. He raced the powerful ship across the plateau and dived it off the edge. For one horrible moment he could not bring the nose up. Down and down they plunged. Then his controls caught and he eased the stick back.

As he spiraled upward the whole world seemed to explode. The top of Umm el Biyara became a shambles as the six bombers, in route column, laid their eggs.

Bill leveled off at five thousand feet with Shorty beside him. Far off to the west he saw the eighteen British planes in pursuit of the six enemy ships. He locked his controls and spoke to Shorty.

"Sandy's out cold," he said.

"Is he badly hurt, Bill?" Shorty asked, his words clipped and anxious.

"He'll do," Bill said. "I'm going to sit down on the airport at Ma'an. Our job is finished."

THAT same evening, Wing Commander Kestrel, Bill Barnes, Shorty and Sandy sat in Kestrel's quarters. Away to the east the desert wind was moaning again. Now and again a camel bellowed a protest at the desert night.

"You've helped break the back of the revolt at the very beginning," Kestrel said. "Serj el Said, the Arab leader, is dead. Four of our men paid the cost for treason, Hector by his own hand. The bribe offered them must have been high. It is hard to admit but true that a few scattered men in any country may become traitors. Most of the civilian fliers working for Serj el Said are dead. If we could only bring poor Douglas back I would be satisfied."

They sat silent for a moment, listening to the soft sighing of the wind.

"If there is anything, any way I can show my gratitude to you, Barnes, anything I can do for you, I---"

"Listen," Sandy broke in, trying to grin through his bandages. "There is something you can do for me!"

"Name it, Sandy," Kestrel said. "Get me an Arabian horse and ship it to Barnes Field," Sandy said eagerly. "You killed mine when you bombed Umm el Biyara."

"That's an order," Kestrel said, "that will be carried out."

"What in the world," Bill asked, "will you do with a horse?"

"Do with him?" Sandy said. "What do you think I'll do with him? I'm going to use him to realize one of the ambitions of my life. I'm going to win the Kentucky Derby!"