Skeleton From the Sky

ANOTHER DRAMATIC "PHILIP STRANGE" MYSTERY

By Donald E. Keyhoe

Author of "Hell Over China,” “The Mad Squadron, etc.

DEATH'S GRIM MOCKERY Fifty feet of steel was the staunch bulwark which fortified the hidden vault wherein the allies concealed the vital plans of their Western Front offensive. Impenetrable, no bomb could blast this massive shield, no human being could pierce it to pilfer those battle secrets. Nevertheless, some phantom power had trapped that stronghold, not once, not twice, but three times! And now a gruesome figure from the grave glided out of the darkness to mock the defenders of that mystic crypt.

CHAPTER I

THE GUILDED SPECTRE

For the second time in as many minutes, Captain Philip Strange had the uneasy feeling that he was not alone in the sky. Wiping his oil-smeared goggles, he peered over the shielded exhaust stacks of his Spad into the somber darkness of the night. Though Paris lay almost directly beneath his droning ship, he could see not a single light, not even a hint of the faint emerald gloom which the Seine sometimes reflected from the green war-lamps on its many bridges.

It came to him suddenly that there were no lights. The French capital lay there in solid blackness, like a thing afraid.

The G-2 ace stared down a moment longer, thinking of the millions of humans hidden there below, wondering at the cause for that somehow sinister blackness.

The two messages which had brought him at full-speed from Chaumont gave no clue. One had been from Marshal Foch to Colonel Jordan, chief of G-2, requesting that he personally investigate a serious information leak in Paris. Jordan, ill from overwork in connection with the approaching offensive, had detailed Strange to represent him. The other message

had been from Major Andre, the explosive, lovable little Frenchman in charge of French air intelligence. It was in the personal code which he and Strange had worked out, and decoded it ran:

Meet me at Fifth Defense Escadrille, Paris, at ten tonight. Most urgent. Tell no one, and cover your trail.

At one time, Strange would have smiled at such a message, but he had learned that Andre never called for help until the need was desperate. With his mind still on the two messages, he nosed the Spad into a flat power-glide across the darkened city and toward the spot where he estimated the defence field to be. He had purposely swerved to avoid the banned zone of approximately five miles in diameter, prohibited to all but defence pilots after nightfall, but he knew that he might have drifted to one side. He was gazing down, ready to signal or swing off quickly in response to a probing searchlight. When somewhere down in the blackness a German Maltese Cross suddenly glowed.

Strange sat up, banked sharply to keep the cross in sight. For a second he thought it was painted on the wing of a Boche plane. But then be realised it was not moving! He shot a look at his altimeter. The Spad was less than two thousand feet high. Seen from this altitude, a cross of such appearance would be about twenty feet from tip to tip if painted on the roof of the average Parisian building.

Almost straight behind him, and about three miles distant, a searchlight stabbed the night. It was joined swiftly by two more beams, and together the three poked wildly around the sky to the north-east. Strange looked back over the Spad's tail, but could see no other ships. He was turning for another glance at the glowing German cross when something flickered in the blackness above him. The blurred flickering steadied, became the outlines of a bony, gleaming hand.

Quickly, the bony wrist extended itself, became a luminous arm. The arm whipped back in a writhing motion, and before Strange's astonished eyes a glowing skeleton materialised in a flash, as though it had dived headlong through a door opened in the sky.

As the spectral figure pitched downward, Strange instinctively ruddered aside. With a second jolt of amazement, be saw the skeleton straighten out, keeping pace with the Spad, its bony arms and legs flailing wildly us it tumbled toward him.

In his first start at sight of this gruesome thing, Strange had clenched his Vickers trips half-way together. Now as he kicked aside, his thumb tightened and the left-hand gun shot out a stream of tracers. The skeleton jerked to one side, leaped up into the night, twisting and writhing like a thing in agony. Strange pulled the stick back as the bony figure swung above his ship, The Spad roared up in a climbing turn, its wings hiding the apparition from view. Levelling out, the G-2 Ace looked quickly for it but saw no trace.

The Maltese Cross had also disappeared. Recalling his former course, he glanced hastily at the distant searchlights to determine the approximate location of the cross for later investigation. Then suddenly the huge wings of a _Gotha bomber showed in one of the beams, but this monster ship vanished in the darkness at almost the same instant he saw it. Then he sighted a smaller ship darting past the searchlight beam and pitching down steeply.

The Spad abruptly rocked as though in a back-wash of air. Strange snatched at a toggle, dropped a flare and zoomed. In the half-second before the flare lit, the skeleton reappeared, above and to the right, He banked instantly, intending to put a burst through it. To his dismay, it spun crazily at the same moment and whirled back toward his prop. He booted the rudder, then yanked the throttle as he saw it would hit the right wing.

The impact and the dazzling light of the flare came simultaneously. There was a jolt, and the skeleton hit spread-eagled against the Spad's crossed wires. Half wedged by the impact, partly held there by the pressure of the slipstream, the ghastly figure leered across the wing at Strange. By the radiance below, he had a clear look at it as he pushed the throttle open again. A pair of airman's goggles hung down around its bony neck, where the wind pressure had apparently forced them.

From its toes to the top of its hideous, grinning skull it was a gleaming, golden color. But there was nothing to show how it had stayed in the air and performed its weird maneuvers.

Strange's attention was centred only a few seconds on this grisly visitor from the sky, but during that interval the Spad was silhouetted by the descending flare. A savage pounding at the tail woke him to his peril. He snapped into a tight turn, looked hurriedly for the ship from which the burst had come.

An Albatros was whipping around after him, guns blazing. It was this ship which had dived past the Gotha in the searchlight beam. He clamped the trips as he tightened the bank, and Vickers slugs nipped at the Boche ship's tail. The pilot hurled his plane into a split, with Strange grimly following through. The skeleton's left arm fluttered madly in the wind as he cut loose again with the guns, and he saw that there was some_thing small and shiny fastened to its wrist. There was no time to see what it was, for another Albatros had pitched down out of the night, and one of the Gothas was almost above him.

The tail of the first Albatros was nearly in his sights when a blast from the Gotha nose-gunner raked his right wing. Strange stabbed a brief barrage at the Boche in front of him, rolled furiously from under the other man's guns. The skeleton's head was twisted around grotesquely. Gotha bullets had shot away the goggles and pierced the skull, but the now unprotected bony face leered more mockingly than ever, as though daring the Germans to do their worst. Strange swore, for the Albatros pilots needed no such challenge.

The Spad shook under a fierce crossfire, as the two Germans plunged in. Strange crouched, yanked the stick back hard. Tracers scorched past his head. A dozen solid slugs ripped open the padding between the guns, crashed a wicked pattern in broken glass and metal along the instrument board. A jab at the left rudder, and the Spad hoiked out of the fusillade into a chandelle. One of the fighter pilots left off firing as the Gotha above blocked his aim, but the other zoomed with spandaus hammering.

Strange whirled back under the bomber, drilled up into its blind spot. Two furious bursts smoked from his guns before be was forced to dart aside. The Gotha reeled, tilted onto its left wing. As it hung there, its pilot fighting to recover control with one motor dead, both the nose and rear-pit gunners cut loose with torrents of lead. From a Parabellum in the rear, two deadly red lines lanced down at the pivoting fighter. A lift-wire parted with a shrill ping in the roar of motors and guns. The trailing edge of an inner bay strut whizzed back, its bullet-torn fragments flying. The main piece struck Strange a blow which his padded helmet only half absorbed, and for a moment his senses spun.

A trickle of blood came down under his goggles as he renversed toward the Gotha. He dashed it from his eyes with a savage shake of the head. The skull shook between two vibrating wires, leering at him like a mascot of death leading him to destruction.

"To hell with you!" he muttered, and tripped the guns as a Boche wing filled his sights. An Albatros staggered sideways, dipped, and came up with Spandaus winking hot and red. Strange stood on the rudder with a vicious thrust. "Take it!" he snarled, and for a gun- crashing second their two streams of tracer crossed. The German pitched back in his seat, clawed wildly at his breast. His ship, unguided, went up as though for a mad, gleeful climb, wrenched off suddenly and rocketed down into the gloom.

By now, a hundred searchlights were waving from all parts of Paris, and through their pointing white fingers half a dozen Gothas doggedly forced their way. French defence planes, Breguet two-seaters, and thin-winged Nieuports, came angling up from three directions, the pilots warming their guns in quick, eager bursts as they climbed. One, a dun-coloured Breguet, was higher than the rest—the only French ship in range of the German raiders. Strange saw the gunners of two Gothas open fire as it zoomed into the battle.

The man in the rear of the Breguet suddenly thumped the pilot on the back and pointed toward the Spad. With a quick swerve, the pilot hurled the two-seater after Strange. The G-2 Ace had aligned his guns on the Gotha nearest him. Then just as he squeezed the trips, the Breguet's cowl-guns flamed. He rolled hastily, out of the French pilot's fire—but under the guns of the Gotha! With a fierce cry of triumph, the Germans swivelled their Parabellums to riddle the Yankee ship. His speed half-lost from the roll, Strange put everything into one last crazy skid. With Vickers blasting, the nose the Spad traversed the lumbering bomber, and raked squarely by both guns, the Boche in the bow cockpit dropped in a bloody heap. In a frenzy, the rear-pit, gunner slammed his twin-mount around at Strange. The G-2 pilot sat like a figure in stone as the Spad slowed to a stall. A murderous hail tore into his wings, gouged across the cowl—then his thrashing Vickers found their mark.

In the shifting glare of a searchlight, the gunner's face became a horrible, scarlet mask. The man tottered, collapsed over his smoking guns, and the stalled Spad lunged down like a cracked whip. Strange let it dive until the wires howled, then zoomed steeply. The Gotha was in the first turn of a spin, its mighty wings rotating ponderously. A bomb shot out at a diagonal from the starboard rack, and suddenly the air was filled with the falling missiles, as the Germans frenziedly tried to balance the stricken ship and recover from the spin.

Strange whipped to one side, eluded a bomb by only a few feet. The Breguet appeared just above him as be chandelled clear. Instantly, the rear-pit man swung his Lewises. Strange hurled the Spad out of range, waggled his wings in a hasty signal. The pilot of the two-seater, a diminutive figure, sprang up in his pit as a search-light fell across Strange's face, and when the G-2 Ace recovered from the brief glare in his eyes he saw the pilot motion for the gunner to cease firing. The gunner pointed fiercely toward the gleaming skeleton in the Spad's wing, and again swung the twin-guns.

Dropping his controls, the little pilot whirled and slammed his fist to the other man's jaw. The gunner sagged down into his pit, and the pilot jumped around to his controls. In the fluctuating glow of the constantly shifting searchlights Strange glimpsed a swarthy face and bristling moustaches. It was Major Andre.

The little Frenchman flung him a hurried sign of recognition, pointed toward the skeleton. Strange shook his head, raised his hands in a baffled manner. Andre stared, ruddered in closer, then jerked his thumb toward the defence field south of the Porte de Bercy. Then just as the two ships were angling across the Seine, a roaring explosion shook the sky. Strange turned in his seat as flame lit the heavens. The Gothas had turned back. and one had been caught by a zooming defence pilot. Blasted by its own bombs, the huge ship was falling in fiery fragments into the heart of Paris.

Three Albatroses suddenly detached themselves from the fleeing bombers and plummeted down at Strange and Andre. Strange pulled up in a screeching Immelmann, caught the tail of one attacking ship as he came out at the top. The flippers and rudder disintegrated under his spouting guns, and the diving Boche went onto his back. The violent force snapped his safety-belt, and out he went, tumbling head over heels into space. Strange felt nausea grip at his stomach, jerked his eyes from the doomed German. The other two Albatroses were converging swiftly on the Breguet. Andre threw the heavier two-seater around in an amazing renversement, clipped an Albatros wing-tip in passing. The other Boche made a lightning turn, crouched behind his Spandaus. The guns were spurting, gouging crookedly across the Breguet's tail, when Strange struck.

Five feet behind the German's cockpit, Vickers lead smoked through fabric. The pilot whirled in his seat, went white with terror. Before he could move, a dozen slugs tore through his twisted body. As Strange let up on the trips, he saw the German's mouth open in soundless scream, then the life fled from that tortured wretch and the Albatros plunged toward the ground with a riddled corpse at the stick.

The third Albatros was racing eastward, two Nieuports on its tail. By this time, archie batteries were crashing away at the remaining Gothas, which were beyond the point where they would fall into Paris. Andre signaled eloquent thanks to Strange, quickly motioned away a Nieuport pilot who was closing in on the Spad. Flying side by side, the two air agents nosed down toward the Fifth Defense Escadrille, which was now marked by a "T" of flares.

Andre landed first, and as Strange taxied in behind him he saw that the man in the rear cockpit was gaining his senses. The two ships stopped close together not far from the administration offices, and both engines died into silence. At once, the furious voice of Andre's companion was audible.

"You will pay for this insult, monsieur, on the field of honour!"

"It would give me great pleasure to further beautify your face!" Snorted Andre. "But I have no time to waste with you now."

He hopped down and ran toward the Spad as Strange climbed from his pit. The other man followed—a tall blonde officer wearing Commandant's insignia, like that of Andre save that he had no wings. His eyes, heavy lidded behind his goggles, had a murderous look, accentuated by the savage twist of his mouth where an old scar lifted it at one corner. Strange had never met the man, but he recognized him from photographs as Major Victor D'Orcy, notorious as a duelist before the war and now an officer attached to the French General Staff.

Andre had almost reached the Spad, with D'Orcy stalking behind him, when a bearded Capitaine ran up with a squad of Poilus. He took one look at the skeleton in the Spad's wing.

"Sacre Dieu!" he said shrilly. "So here is the explanation of our mystery. Sergeant, arrest this Boche espion!"

CHAPTER II

SKY TRAP

A non-com sprang toward Strange, but Andre intervened. "Wait!" he cried, "This man is no German. He's an American—here to help us!"

"German or not," fumed the Capitaine, "it is clear he is a spy and has been guiding the Gothas by means of this skeleton trick."

"Right!" grated D'Orcy. "But for some peculiar reason, Major Andre defends him, even to the point of attacking an officer of France."

"I suppose I should have let you shoot down our greatest Allied agent!" retorted the little major.

"Allied agent?" exclaimed the bearded Frenchman.

"Oui" snapped Andre. "Send your men out of earshot."

The Capitaine grudgingly obeyed, but he still kept his pistol lifted.

"Now," said Andre, when the squad and the assembled mechanics had fallen back, "I shall explain. This is none other than Captain Strange, the American Intelligence officer I came to meet."

The French captain's mouth popped open at mention of the G-2 Ace. Even D'Orcy seemed startled into silence—but only for a moment.

"Famous men have been traitors before," he said harshly. "If he is innocent, let him explain that skeleton on his ship's wing."

"I will—but you probably won't believe it," Strange responded. Then he related what had happened.

"A skeleton from nowhere!" snorted D'Orcy.

"Surely. Major Andre," said the bearded Capitaine, "you do not believe this silly story?"

"Captain Jacques," said the little major, "I have learned in this war to believe almost anything. After all, this fits with the account of the skeleton which fell into the Rue Grenelle two hours ago."

"But that one was dropped, you told us—while this American says his skeleton was flying along, like a bird."

"I said it appeared to be flying," Strange interrupted.

"There's a difference."

"The story is preposterous," rasped D'Orcy.

"This Yankee spy has hoodwinked everyone and is serving the Boche. As an officer of the Staff, I order—"

"You order nothing!" exploded Andre. "I am in charge here. Pull your tongue back into your head!"

"I will demand satisfaction for this!" snarled D'Orcy.

"And I will be at your service, when I have nothing important at hand," snapped the little major.

Strange stepped between the two men. "Look at this skeleton," he said curtly to D'Orcy.

"You'll see it is not fastened to my ship."

Captain Jacques shoved a bucket of burning waste close to the Spad as D'Orcy and Andre turned. The gilded bones shone like gold in the light, and the gleaming, bullet-pierced skull grinned mockingly at the four men. One foot had been shot away, as well as several ribs. But the bony figure still hung together.

"It must be hooked together with wires," muttered Jacques, "like those in the medical schools. Oui, I am right."

"And Captain Strange is also right," said Andre, pointing. "The skeleton is not secured to his plane. You can see where it struck the wires and slid down. There is the same luminous gilt on the wires as on its bones."

Jacques scratched his bearded jaw, turned to Strange apologetically. "I was too hasty, mon Capitaine. But you must admit it is most incredible."

"I don't blame you," said Strange. "I would hardly have believed it myself. The question now is how it was done."

D'Orcy's lips curled. "Surely the great Captain Strange is not at a loss to explain a simple matter like a flying skeleton?"

Strange ignored him and turned to Andre. "You said another skeleton had fallen from the sky. Was it painted like this one?"

"From the report, yes," said Andre. "An agent de police called the War Ministry as I was preparing drive out here. He said a mysterious bomb or shell which fell without a sound had partly demolished a house on the Rue Grenelle, and that a luminous skeleton was seen to fall an instant before the explosion. Parts of the skull and the bones were found in the ruins along the sidewalk.”

“The explosion was not silent?" queried Strange.

"No, that was normal, apparently. But whatever it was, it fell silently, and it could not have come from a plane. Sound rangers were on the alert, fearing more of these devilish Gotha raids. A plane would have been heard—unless the Boche has found means for making engines and propellers soundless."

Strange climbed onto the wing of the Spad, recalling the object he had seen on the skeleton's wrist.

"These raids, then, have been unusual?" he asked Andre as he reached the figure.

"Of an uncanny accuracy," said the little major sourly. "Ammunition factories, aeroplane plants, and other vital industries, have suffered most. The darker the night, the more the Boche seems to like it. Of a certainty, they have been guided—what is that, mon ami?”

“An Identification tag," said Strange. He lifted the dangling left arm, but the wire at the elbow-joint broke and the forearm dropped to the ground. Jacques picked it up gingerly, and turned over the metal disk chained around the wrist-bones. Suddenly his face went ashen and he dropped the skeleton's arm.

"Mon Dieu!" he cried hoarsely. "We have found Albert Lemoir!"

His voice carried to the staring poilus, and Strange could sense the horror which swept over the group.

"Who was Albert Lemoir?" he said to Jacques.

"One—one of my pilots," the capitaine mumbled. He cast a sickened glance toward the skeleton, turned blindly toward the administration building. "I will be in my office, Major Andre— if you need me."

'Poor fellow," Andre whimpered, as Jacques stumbled away. "Lemoir was like a son to him.”

“But what happened to Lemoir?" asked Strange, climbing down from the wing.

"He took off from this field one night and failed to come back. That was a month ago. Since then, two more of Jacques' pilots have disappeared in the same way."

"Were they on special missions?”

“No, on routine night patrol, flying Nieuports."

Strange picked up the arm of the skeleton. Some the gilt paint smeared off on his hand. He held the gruesome relic toward the light.

"Was there any tag on the skeleton which fell in Paris?”

“I don't know," said Andre, "but I imagine it was similarly painted, for the gendarme reported it as luminous.”

“You told us that part of a helmet and some shattered goggles were found," D'Orcy put in tartly. "Unless your agents are as stupid as some of their seniors, they should be able to tell whether the fragments are from French or German equipment."

Strange spoke before Andre could answer the gibe.

"This skeleton had a pair of goggles hung around its neck, but they were shot away in the fight. However, that wouldn't help us solve the problem of where they came from." D'Orcy's scarred face twitched into a sneer.

"They came from Germany; it takes no super-mind to guess that.”

“For which you should be thankful," smirked Andre. The duellist's heavy eyelids narrowed. But he kept his temper this time.

"The problem," he said to Strange, "is not where they came from, but how they materialised over Paris. It is evident to me that the Boche butchers are using the skeletons some way to guide their bombers. Perhaps it is only a scheme to frighten our people, dropping skeletons of Frenchmen into the city."

Strange shook his head. "After four years of war Parisians do not frighten that easily. No, commandant, there is something deeper. I have a vague feeling that when we examine all the evidence—" he broke off, looked at Andre. "You must have had some other purpose in sending for me, since the first skeleton was dropped after your message to Chaumont. Does it shed any light on this affair?"

The little major thoughtfully twirled his moustaches.

"I asked your help because of a grave leak in information—that was just before I learned that Marshal Foch had sent word to Colonel Jordan. But yes, there could be a connection."

D'Orcy scowled.

"I understood the matter was to be kept strictly confidential until the conference at the Allied Intelligence Pool tonight."

Andre made an impatient gesture. "Colonel Jordan was ill; he sent word that Strange was to represent him and G-2." He looked back at the American agent.

"Mon ami, I can see but one possible link. Whoever has guided the Gothas to those important targets—whether by skeletons or other means—must have had direct help from Paris. In a word, it also is what you call a leak, n'est-ce pas?”

“I think I can help you there," said Strange, He described the Maltese Cross which had appeared down in the darkness. "Parbleu!" exclaimed Andre. "And you think you could locate the place where you saw it?”

“Within a block or so," Strange replied, "but you'd have to arrange for the searchlights north of Vincennes to be turned on. I took bearings on the centre one.”

“That will be simple. We will take off at once,”

“But what of the banned zone? The cross was somewhere in that area, over on the Left Bank.”

“I will have Jacques telephone the defense control officer and explain," said Andre. "He can also have mobile guards and police ready to surround the area we indicate. Oui, and we can in addition save time we would lose driving into the city by obtaining permission to land in Paris.”

“In Paris?" Strange said in surprise.

"Ah, I forgot you did not know. To help combat these accursed Gothas, we have established two special city defence-flight units, roping off some of the broader streets for take-off and landing purposes. On the Left Bank, the Boulevard Raspail has been blocked from St. Germain almost to the Rue de Sevres and also a section of the Rue de Varennes for use in case the wind is from east or west. Six Nieuports and three Breguets are kept there—you saw some of them attack the Boche tonight."

Strange nodded. Then Andre turned, looked coldly at D'Orcy.

"If you care to fly into Paris, I will take you in the Breguet—as matter of duty. We can follow Captain Strange."

The other man's scarred mouth twisted. "I have had enough of your company for one evening. And my chauffeur can have me through the Porte de Bercy before you are off the ground."

He stalked away, and in a moment a long Mercedes-Benz swept past headed for the Bercy-Paris road.

Strange looked inquiringly at Andre. "I supposed he came with you.”

“Not if I could avoid it," retorted Andre. "He brought an agent from the Intelligence Pool for one of Jacques' pilots to carry across the lines. The plane had just taken off when I arrived. Monsieur D'Orcy and I were exchanging polite insults when we heard the Gothas and their escorts. In the heat of excitement, I unwisely permitted him to act as my rear-guard in an attack on the Boche.”

“And then knocked him out when you needed him most," said Strange "I haven't really thanked you for that, Andre—he was bent on finishing me after he saw the skeleton.”

“I need no thanks, mon ami. It was quite a pleasure. Indeed, I am sorry I did not remove a few of teeth. Now that I think of it, I am in your debt for picking that Albatros from my tail while D'Orcy was sleeping. So the honours are even."

Andre gave orders to the waiting mechanics, and when he returned from the office a few minutes later the Breguet's Liberty motor was again rumbling.

"I have given word that your Spad and the skeleton are not to be disturbed," he told Strange. "My section will, of course, wish to photograph everything."

Strange tapped the capacious pocket of his leather coat. "I hope you won't mind. I'm taking that forearm with me—I'd like to examine the bones with the gilt removed.”

“You have some inkling about the matter?" Andre said eagerly.

"Just a vague idea that it all isn't what it seems. It might also be a good idea to look at the skeleton which fell into the Rue Grenelle.”

“There will be no trouble there. Lieutenant Bayard, of my own office, has been sent to head the investigation. But we had better hurry if are to locate that signalling point in time to do any good."

All the defence ships of the escadrille had landed by this time, and as the Breguet roared up into the night the flares were quickly extinguished. At Andre's suggestion, Strange had taken the front cockpit, so that he could fly the ship and check the bearings, He climbed to fifteen hundred feet, the altitude at which he had first seen the cross, and then carefully set about flying the approximate course he had followed. In a few moments the searchlights north of Vincennes were switched on, shifting to point steadily into the sky.

Watching the compass and the lights alternately, he waited for the instant when the bearing would be the same as that he had noted before. He realised almost at once that he had been flying closer to the banned zone than he had suspected previously.

"Tell me when we are over the spot," Andre's voice came through the speaking-tube to his helmet. "I have a white-star rocket ready to fire so the police will know where to close in.

"It will be in about a minute," Strange answered. "I'm going to spiral down over the place where I think the cross was."

The two-seater roared ahead until, sighting carefully on the Vincennes lights, he estimated they were in the right position. Closing the throttle, he sent the Breguet down in a fast, tight spiral to offset possible drift. He had barely completed one turn when from half a mile distant a searchlight beam pierced the blackness and fastened upon the ship.

Too swiftly to be counted, other searchlights blazed up and swung toward the Breguet. Strange had ruddered out of the first beam, but the dazzling radiance of a dozen more at once engulfed the two-seater.

"Name of a pig!" Andre was howling through the tube. "I told them—"

Crash! A blob of red flame appeared just off the Breguet's right wing, and an exploding archie shell rocked the ship. Strange rammed the stick forward, trying to dive out of the lights. More A-A guns were blazing from the tops of five or six buildings, and a storm of shrapnel suddenly filled the air.

"Sacre bleu!" bawled the little major. "It is a trap! We have been betrayed!"

Strange plunged the Breguet away from two light-beams which flashed down after them, then kicked around in a furious skid. The speed of his dive offset the manoeuvre, and for a moment they were out of the blinding glare.

"Quick!" shouted Andre. "Land in the Boulevard Raspail before those fools scatter us in little pieces!"

Strange shot a look over the side. The Seine and the Ile de La Cite were directly beneath, and the square towers of Notre Dame seemed to be leaping out at the ship. He whipped to the left of the old cathedral, disregarding a blast of machine-gun fire from the roof of the nearby Prefecture de Police. Straight ahead, two rows of tiny lights, red and green, abruptly outlined the upper half of the Boulevard Raspail. The next second, a lane of white appeared between the parallel lights, and down this lane three Nieuports came streaking into the air.

The defence patrol had been loosed against them!

CHAPTER III

DEATH ON THE RUE GRENELLE

The leading Nieuport zoomed dizzily, its pilot warming his guns in three quick bursts. Strange renversed, pitched through a searchlight beam, saw the glimmer of the Seine again below him. A dark shape charged across the river, grew into the menacing bulk of a coal-black Breguet from the defence station on the Right Bank. With its exhaust stacks perfectly masked, and only the white faces of the pilot and gunner to reflect the light, it was almost on them before Strange saw it. He nosed down, hurled the Breguet under its black sister-ship. Suddenly he heard the rear-pit guns clatter.

"Stop firing!" he shouted at Andre. "That's one of your own planes!”

“I am only keeping them off!" Andre yelled back. "Nom d'un nom, get us down before I lose my temper and shoot that pig of a pilot!"

Strange threw the Breguet into a vertical bank and sent it thundering back across the Seine. Frightened crowds fled from the quays and the bridges as gunners atop the nearest buildings flung a murderous fire after the ship. The black two-seater slid down on one wing, rear-pit guns flaming. Tracers left smoking holes in Strange's cowl, scorched on into the wings. The G-2 Ace booted his rudder, escaped a second blast, and pitched the Breguet down into the narrow Rue de Bellechasse.

Soldiers and civilians around the Quai d'Orsay railway station broke in a panic as the ship roared past, hardly fifty feet from the ground.

The black Breguet zoomed, was joined by the three Nieuports, and the four shlps raced overhead, waiting for their quarry to climb. With a desperate skill, Strange threw the two-seater onto its left wing-tips as they reached the Boulevard St. Germain. The ship grazed a streetcar, straightened out in a semi-gloom which was quickly broken by the lights of the blocked-off avenue ahead.

Fuzzy tracer-lines stabbed down across the plane's nose as Strange jerked the throttle. Cowl-guns blazing, the black Breguet dived into the boulevard, one of the Nieuports following for an attack if the other pilot missed. A muffled howl of fury came through the tube to Strange's helmet, and Andre flung a burst at the black ship's prop. The defence Breguet stood on its tail, forcing the Nieuport to a hasty zoom over the rooftops, and with a vast relief Strange cleared the obstructions at the head of the Boulevard Raspail and let the riddled ship settle to the pavement.

It stopped about two hundred feet from the intersection with the Rue de Varennes along the sidewalk of which fuel drums, small tents, and a communication booth had been placed for use of the defence patrol. Mechanics and officers dashed out with drawn guns, and the Breguet was speedily surrounded by an angry group.

"Bring out les Boches!" bellowed a stentorian voice, and a lantern-jawed first lieutenant thrust his way through the crowd. Andre hopped up on the rear seat before anyone could seize him.

"Imbecile!" he shrieked at the lieutenant. "If you are the one who did this, I will have you in the Bastille!"

The other man's mouth opened in amazement. "Commandant Andre!" he gasped, and the suddenly quieted mob stared at the little major. "But why did you send such an order?”

“Order? What order?" raged Andre.

"Why, to have your plane brought down," faltered the lieutenant. He cringed under Andre's glare. "I had no part in this, commandant—I just arrived, thinking an Intelligence officer might be needed—”

“Stop whining and tell me about this order," snapped the little Frenchman.

"It was supposed to have been from you, telephoned from the Fifth Defence Escadrille," said the other man, unhappily. "You—the message said that two German spies had stolen a Breguet loaded with bombs and were flying here to destroy the planes kept on the boulevard. The order was for the anti-aircraft gun crew to wait until the Breguet was over the Seine before they fired so it would not fall in a crowded street.”

“Who told you of this order?" demanded Andre.

"It was relayed to me, at the wrecked house in the Rue Grenelle, so I could take my men and go to the river and help capture the spies if they escaped death in the descendu. You can confirm all this by asking any of these officers.”

“Oui, major, it is the truth," hurriedly assented a flying-corps lieutenant. "I received the word myself, from the defence control-officer.”

“The control-officer is a numbskull," Andre said fiercely. "I sent him a message, yes. But no one with human intelligence could have so construed it."

He climbed from the ship, and Strange and the first lieutenant followed him into the communication booth.

"This," said Andre, pointing to the lantern-jawed officer, "is Lieutenant Bayard, as you probably have guessed. There is no danger in letting him know that you are Captain Strange. He is not so dumb as he appears."

Bayard reddened, awkwardly shook hands with the G-2 Ace.

"I have heard much about your exploits, mon capitaine. Major Andre says you are the greatest agent the war has produced.”

“Excepting myself, of course," Andre chuckled, with a sudden return to good humour. "Now, if you will excuse me—" he picked up a phone, and for the next minute or two the air crackled with Gallic expletives. After another rapid conversation, be turned to Strange and Bayard.

"It was no mistake by the control officer. The order was not the one I outlined at the Fifth Escadrille. Either Jacques made a mistake or the line was tapped somewhere and a false order substituted for the one I gave. We will know in an hour or two; I have left word for the in_formation to be telephoned to me at the Intelligence Pool.”

“My car is just around the corner," said Bayard. "I can take you to the Pool.”

“Tres bien," said Andre. "But wait." He turned to the G-2 Ace. "Strange, do you still wish to see that other skeleton?”

“More than ever:” replied the G-2 Ace. Judging from that attempt to get rid of us, we must be on the right track.”

“You spoke of another skeleton?" said Bayard, when they had reached his car. Strange waited until the car was started, then withdrew the bony forearm from his flying-coat pocket. The hand, which he had doubled back, had lost several finger bones during his violent manoeuvring of the Breguet, but the identification tag was intact. He briefly explained to the astonished Bayard how he had encountered the skeleton, then asked "Did you find a tag on the first skeleton?”

“No," said the homely Frenchman, "but not all of the bones were recovered. Also, some of the bones might have been carried away as souvenirs before the police arrived. There are always such morbid ones around,”

“Were the bones you found gilded like this?" queried Strange. "Freshly painted, I mean?”

“They did not glow so brightly." replied Bayard, taking the bony arm in one hand and steering the car with the other. "And I do not think it was fresh paint. It did not come off on my fingers like this."

Strange nodded, took back the skeleton arm and regarded it silently. Bayard spoke over his shoulder to Andre. "I suppose after all this, commandant, you will put Sergeant Douville on the case again.”

“Again?" said Andre sharply. "He has never been taken off the case. Hasn't he reported to you as usual?”

“I have not seen him in five days," Bayard replied with a note of alarm. "I thought you had given up hope about Lemoir and the others, and hence had detailed him elsewhere.”

“Nom de Dieu!" groaned Andre. "My best 'bloodhound' disappears and no one tells me for five days.”

“Perhaps he stumbled on a clue," said Bayard hopefully. "What was the last word from him, if you don't mind my asking?" Strange interposed.

"He was going out to question Captain Jacques' pilots again," said Bayard. "After that, I do not know.”

“Find out if he told Jacques where he was going from there," ordered Andre, "and put some one on his trail.”

“I will telephone tonight—but here we are at our destination."

The wrecked house had been an imposing three-story structure, fit even to be on the same street with the Russian Embassy half a block away, though time had faded its glazed red brick. The explosion had wrecked the front of the building and part of the right-hand wall, so that the upper floors and the roof had crumbled and sagged with a consequent spilling of broken furniture, jagged pieces of flooring and other debris. Most of this filled the space between the sidewalk and the undamaged part of the house, though some of the wreckage lay out in the street. All of the windows were broken, and a grilled iron door hung drunkenly by one hinge on the right side of the structure.

The entire house and half of the street in front of it had been roped off, and workmen were greeting a high wooden barrier to protect the place from looters. Several policemen kept spectators well beyond the ropes, their dark-green war lanterns bobbing back and forth.

As Strange and the others stepped from the car, a burly sous-officer started to bar the way, then saluted as he recognised Andre and Bayard.

"Were the spies caught?" he said to the lieutenant.

"The spies," Andre cut in dryly, have been taken care of. We have come to inspect—" He suddenly broke off. "Ah! What have we here?"

An ill-clad, skinny old man with a week's stubble on his chin was being led away protestingly.

"We caught him trying to steal from the ruins," exclaimed the sous-officer. "He crawled under the ropes while we were watching the air battle.”

“I was only after what was— mine," cried the old man. "I am no thief. I am an honest man who—" He quailed suddenly under Andre's keen gaze.

"I have seen you before," snapped the little major. "Who are you?”

“You are mistaken, m'sieu," mumbled the Prisoner. "I do not know you. I never saw—

"He says his name is Joseph Daru," interrupted the sous-officer, "but I think he is lying.”

“Was he by any chance trying to steal the bones of that skeleton?" asked Strange.

"I could not say, monsieur," shrugged the non-com. "It is possible; he acts a little mad."

The old man burst into a cackling laugh. "The bones! Why should I steal the bones when I know—" he sprang back as Strange and Andre jumped toward him.

"When you know what?" Andre said harshly. The old man cowered back against the wooden barrier, and by the faint green glow of the war-lanterns Strange saw a fearful look come into his eyes.

"Nothing, m'sieu le commandant," he quavered. "I was but going to say that I know bones have no value. Who would buy old bones?”

“Don't lie to me!" thundered Andre. "You know something about this affair, and I'll get it out of you if I have to wring your scrawny neck!”

“Give him to me for a little while," said Bayard. "A few minutes down in the Surete's 'Black Room' will open his lips.”

“No, no—in the name of Heaven, messieurs!" The old man cried wildly.

"So you know the Black Room?" said Andre. "I thought I had seen that face before. Now, will you tell the truth—or shall I send you to the Surete?”

“I will tell you," moaned the prisoner. "Only do not arrest me, m'sieu. My crime is long forgotten— I did no real harm.”

“Speak up!" rasped Andre. "Do you know anything about the skeleton that fell here tonight?"

The old man cringed back at Andre's furious tone.

"Yes, m'sieu," he said hoarsely, "I know all about the skeleton. It came from—" With a. blood-curdling shriek, the old man abruptly stiffened against the wooden barrier.

"Santos!" he screamed, his dilated eyes almost popping from his suddenly dead-white face.

Strange spun around to see what had terrified him, but there was nothing in sight. When he jerked back, the old man's eyes were glassy. His knees buckled and he slowly slid to the ground.

"Mon Dieu!" shouted Bayard. "He has been stabbed!"

A dagger had been driven with terrific force through the wooden plank and into the old man's back. Dripping with blood, the dark blade shone a ghastly hue in the green light.

Strange and Bayard simultaneously dashed for the opening in the almost finished barrier. As they reached the other side, Bayard produced a flashlight and aimed it along the wooden wall. The beam quickly disclosed the hilt of the knife, but there was now no sign of the assassin. Andre and several police appeared, and the little major sent the men scurrying around the house and into the wreckage to search for the killer.

"It is probably useless in this darkness," he said gloomily to Strange.

"If only we had realised at once that murder had been done—but I thought the old fellow was simply frightened at something he saw in the street.”

“I'm not certain that he didn't see something," said Strange. "You heard him call out 'Santos'?”

“Oui, but it is a common name— it does not help us." Andre turned and surveyed the hilt of the dagger as Bayard spotted it with his torch. "A typical Apache knife. Leave it to be photographed, Bayard. There may be fingerprints, though I doubt it."

They went around the barrier to where a gendarme was guarding the corpse. A careful search disclosed only a package of cheroots and a few francs. Andre absently rolled the tips of his waxed moustaches.

"If I had your memory, I would place this poor wretch's face at once," he said to Strange. "But I suppose I shall have to wait until the Rogue's Gallery is searched. I am positive he has a police record."

Strange looked down at the dead man. "It's maddening to come this close to the secret — only to lose it. We should have known, after that trap was set for us, that an attempt would be made to silence anyone who knew the truth.”

“Yes, I should have had him taken in under guard," muttered Andre. "But my foresight is ever poor."

They both turned as Bayard and a policeman hurried toward them.

"Has our murderer been caught?" exclaimed Andre.

"No," said Bayard, "but I found this near the spot where he stood."

He held out a metal tag. Andre snatched it from his fingers, stared at the name etched into the surface.

"Lieutenant Charonne Benet!" he cried. "The second man to disappear from Captain Jacques' squadron!"

CHAPTER IV

MURDER IN THE DARK

"Are you positive," said Strange, "that this was not there before the barrier was put up?”

“I would not swear to it," replied Bayard, "but I think it unlikely'." The G-2 ace wheeled to Andre. "Can we search your Rogues' Gallery tonight?”

“Yes, but we won't have time until after the conference—we shall have to hurry even now. Why not let Bayard do it and telephone the results?”

“All right," Strange answered. "But there is one other thing. I'd like to know everything available about this house—who owns it, who was living in it, Its entire history." Bayard looked puzzled.

"But we already know all that is necessary. It belongs to a rental syndicate and was leased to a Madame d'Aubreil as far back as ten years ago. When she died, a step-son took over the lease. This I learned when I called the syndicate agent about the explosion."

"And this stepson?" queried Strange. "Is at Verdun, and the syndicate agent said he would get in touch with him immediately. The house has been empty since the stepson was called to the colours.”

“What is his name?" demanded Andre. Bayard shrugged apologetically.

"I did not ask, commandant. There was no reason; I was merely reporting the disaster so that the property could be guarded by the owners.”

“Find out," snapped Andre. "Then check our photographs and identify this self-styled Joseph Daru. Put a dozen men at the task—and also see what Captain Jacques has to say about that message tonight. Telephone or bring the information to me at the Pool."

Bayard saluted and hurriedly set about having the corpse removed. Andre enlisted the services of a police chauffeur, and in a minute he and Strange were en route in a borrowed Surete machine.

"A most puzzling series of incidents," said the little major, "but we had better try to put them out of mind until this conference is over. I should warn you that your old enemy, Colonel Beeding, is the senior American in the Supreme Intelligence Council. Hence, you are probably in for some unpleasantness."

Strange lit a cigarette. "Colonel Jordan foresaw that. I have written authority to act independently, also orders to be handed to Beeding commanding him to return to Chaumont at once."

Andre whistled. "I can visualise fireworks, You have been informed, then, as to the main problem?”

“Only that there has been a bad information leak endangering the Argonne offensive”

“It is far worse than that," said Andre. He lowered his voice so that the driver could not hear. "Strange, there is a traitor in the Council itself, where every vital secret of the Allied forces has been discussed!”

“I thought all of the men detailed to the Pool had been investigated thoroughly," said Strange.

"It is so. Such checks have been made from the moment of birth to the present — even to their grandparents—to be sure of their background. In confidence, I can also tell you that each member is watched by agents of our Ministry. And doubtless the British watch the other members—perhaps even their own. Moreover, I suspect your G-2 is not asleep, nor the Italian secret service.”

“I have seen routine reports on the subject," admitted Strange, "though I have had no time to read them carefully.”

“At least you know the purpose of the Intelligence Pool. It was organised to tie up loose ends, so that each Allied general staff could have access to information from every other Allied source—French, British, American. and so on. Every report of interest is sent or brought there and catalogued by experts. Information is released only after a triple-check to be sure it does not fall into wrong hands. Many details of Allied offensives are decided there, with Marshal Foch and others of the High Command sitting with the Council. The most valuable information is kept in a big safe, and there must be at least three of the Council members present when it is opened and during all checking of these records and plans. Also these witnessing members must be of different nationality—a French officer, an Italian, and a British, or a Frenchman, a British, and an American, and so on. Two guards watch the door to the safe-room day and night. All this is necessary, you will agree, when you realise that in the safe are such things as plans of intended offensives and books containing the names and locations of every Allied resident-spy in Germany—also the secret list of agents such as yourself.”

“How many officers are there in the Council?" Strange asked quickly. "Eight, including myself. The others are Colonel Beeding and your Major Brandiston, Major Smythe and a Captain Leeds, for the British, an Italian lieutenant-colonel named Ferrari, a Portuguese named Torres, and that pleasant gentleman you met tonight, Major D'Orcy."

Philip Strange looked at the French major sharply, but Andre shook his head. "I would sooner suspect myself than D'Orcy, much as I dislike him. His hatred of Germany is almost a mania—his first duel was with a German, over a woman, and he later picked quarrels with a dozen more of them. He has distinguished himself in three major engagements, displaying particular ferocity against the Boche. And his family has always been fiercely anti-German. No, D'Orcy is not our traitor. But the difficult part is that neither can anyone of the others be the traitor— unless it be the Devil himself,”

“What do you mean?" said Strange. "After the first disastrous leak— on a matter of action decided by the Council and known only to the eight members—Marshal Foch instructed me to double the men watching the Allied members. Of course, D'Orcy and I have been watched, also—I saw one of Foch's personal agents there at the Fifth Escadrille tonight and we are undoubtedly being followed now. Yet since that first leak there have been two others—of the same nature — but not one of the eight members made a call which has not been checked, or sent a message not intercepted, or met anyone who has not been carefully investigated. In short, only eight men knew the facts on which Germany promptly acted— but it was impossible for any of the eight to have transmitted that information.”

“You're sure no one else in the Pool could have overheard the Council's discussion?" Strange asked. "Quite impossible," responded Andre. "The Council chamber is next to the safe room, and both are soundproof. Also, it is necessary to pass through a small wardrobe-room to enter the chamber, and the door to the wardrobe is kept locked at such times. So you see, mon ami, why I need your help. Like the rest, I am under suspicion. Thus I should feel happier to have it cleared up. But the worst part concerns the offensive. There is enough information at the Pool to wreck the whole Allied drive—if it should fall into German hands."

The police chauffeur, forced to detour widely because of the blocked avenues, finally slowed before a darkened house just off the Rue de Babylone. Two sentries stood before huge iron gates. Andre motioned Strange to follow him, and an officer inside the gates, after recognizing the diminutive major, ordered the two men admitted.

"This is the only entrance to the Pool," said Andre as he led Strange across a circular court to the front door of the building,

"What about the door in the wall along the alley?" Strange said before he thought. "It is guarded and chained shut. But pardieu! How did you know about that door? I thought you had never been here.”

“I know this neighbourhood," Strange said in a careless tone. "I happen to remember that all these houses have exits to the alley."

Andre peered at him through the gloom. "I never thought of you as one to be prowling through alleyways. What was your reason?”

“They always fascinate me— especially Parisian alleys," Strange evaded him.

"Oh, very well," Andre said crossly, "if you wish to be mysterious."

They halted for another identification, entered, then went down spiral stairs until they came to another door about sixty feet below the ground level.

"Unless you know about this also," Andre said with sarcasm, "I might inform you that it is a gas-lock entrance, and that we have just come down through fifty feet of steel and concrete fortification. A protection against bombing, of course.”

“So these are the magic portals," Strange said with mock awe.

Andre snorted, pressed a button, and presently the outer door of the gas-lock swung open. They entered, the door closed, and the inner door promptly slid into a niche. An alert young officer stepped forward, with two poilus behind him.

"The Council is waiting for you and Major D'Orcy, sir," he said to Andre, with a questioning glance at Strange.

"Present your credentials, mon capitaine," Andre told Strange formally. The G-2 ace brought out his papers, hiding a grin at the annoyance still discernible in the little major's voice. The guard officer scanned them carefully, gazed with interest at Strange.

"Marshal Foch sent word you would represent Chaumont," he said.

"Will you sign the register, please?"

Strange scribbled his name, looked around him as he followed Andre. The Intelligence Pool had been constructed with ten offices ranging around the wall in the shape of a U, with the gas-lock entrance at the open part of the U. Three long rows of filing-cases were ranged between the offices. This glorified basement was brightly lighted, but some of the rooms had frosted-glass doors so that he could not see inside. Three or four men were seated at nearby tables, copying data from the files. Others were transferring information to large maps by means of varicoloured pins. The place was almost as quiet as a tomb.

A brass rail separated two of the offices from the rest, creating a narrow passage. In this space stood the two guards Andre had mentioned, one in front of the safe-room door, the other before the entry to the cubicle which served as a cloakroom for the Council. The process of identification again was gone through.

"I could get into the United States Treasury easier than this place," Strange said, as they entered the cloakroom.

"It is also just as hard as this to get out," growled Andre. He closed the cloakroom door, jabbed a button at the entrance to the Council chamber. In a moment the heavy door opened, and the sound of voices was audible. A scholarly-looking American major had unlocked the door. He nodded to Andre, gave a start as he saw Strange.

"How are you, Brandiston?" said the G-2 ace.

"Strange!" exclaimed the Yankee major.

"What are you doing here?"

"Well, as long as I've come this far," Strange grinned. "I'd like to join your august assemblage."

"That's out of my hands," said Brandiston.

"Er—you know Colonel Beeding, of course?"

Strange glanced in at the portly G-2 officer. Beeding's fat face was as red as the wattles of a rooster.

"Where's Colonel Jordan?" Beeding demanded.

"At Chaumont," said Strange. Then he gave Beeding his credentials, withholding the transfer orders until he could present them without embarrassment to the ranking officer. Beeding scowled at the document.

"So you've come to give us the benefit of your advice," he said nastily. "Well, don't forget that I'm senior here!"

Andre hurriedly created a diversion by introducing Strange to the rest of the Council. Ferrari, the Italian member, smiled with a flash of white teeth, and Torres bowed elaborately. Major Smythe, a languid-looking Englishman, replied perfunctorily, but Captain Leeds, whom Strange had met, jumped up and shook hands with a gladness that seemed to be genuine.

"Thank Heaven, you're here, old chap! Maybe you can straighten out this blasted mess.”

“From what Andre has said, I'm afraid you need a wizard," said Strange. He took off his coat and helmet.

"You've been wounded!" exclaimed Leeds, as he saw the dried blood on the G-2 ace's forehead.

"Just a nick," said Strange.

"But what happened?" insisted the Englishman.

"You haven't had a report on anything unusual tonight?" Strange parried.

"No, we've been working like beavers." Leeds motioned toward three red-bound books and a litter of scratch-paper. "Trying to overhaul our spy network to discover where we're vulnerable. Reports come in, but the communications men don't interrupt us except in emergencies."

Strange smiled grimly. "Well, this seemed like an emergency a couple of times." He explained as briefly as possible.

"Poppycock!" jeered Colonel Beeding when

Strange described how the skeleton had materialised apparently from nowhere. "Do you expect any sane man to believe that?"

Strange reached over and took the gilded forearm from his flying-coat.

"Andre will tell you that the skeleton was tangled in my wings when I landed, and here

is part of it."

"Oui, and more than that," snapped Andre.

In staccato voice he described the trap into which they had flown, and all the events on the Rue Grenelle from the partial destruction of the house to the murder of the old man.

"But, I say," protested Major Smythe, "none of this makes sense. And as for a skeleton that flies—why, it is utterly ridiculous."

"Of course it's ridiculous!" stormed Beeding. "This is some damn-fool joke. Captain Strange, you will report to Paris Headquarters and stay there until I've time to attend to you."

"I'm sorry. Colonel," Strange said calmly. "I didn't want to do this, but you give me no choice." Then he handed the elder man his signed orders.

Beeding turned purple, and for an instant he seemed about to have a spasm.

"You framed this whole thing!" he burst out hoarsely. "You've hated me from the beginning — and now you've worked it to disgrace me!"

His voice filled the chamber, almost drowning the buzzer which suddenly rang out. Brandiston opened the door, and Beeding's wheezing voice was abruptly lost in a furious snarl.

"So you thought you had killed me!"

The G-2 ace turned, stared in amazement. There in the doorway stood a bruised, dishevelled figure in a torn and filthy remnant of a French officer's uniform. Strange had to look twice before he recognised the bandaged, bloody face as that of Major D'Orcy. Behind the man was one of the two guards stationed outside.

"Get back to your post!" rasped D'Orcy.

"But be ready—you'll soon be needed!" He kicked the door of the cloakroom hut,

advanced into the chamber.

"Sacre Dieu!" said Andre. "What is the matter?"

"Murdering traitor!" grated the other man. "You ask me that! And to think I never guessed!"

He staggered toward Beeding, gripped the edge of the table to keep from falling.

"And this prized agent of yours, Captain Strange! he's a spy, oui! A spy for Germany!"

A chorus of exclamations filled the room. Beeding's jaw sagged, worked up and down.

"Wh-what do you mean?" he stuttered.

"These two, they tried to kill me!"

D'Orcy's face distorted with fury as he pointed to Andre and Strange.

"I can see they have been telling you some lying story—probably the same as they told Captain Jacques and me. I let them convince me. But they must have been afraid I'd tell what happened—that I'd realise I'd been hoodwinked.”

“Wait!" Andre broke in. "There is some mistake.”

“Yes—your mistake in not making sure I was dead!" D'Orcy's scarred mouth twisted with rage. "You knew I was driving in on the Porte de Bercy road—you two had it planned to drop that flare and attack me with the _Breguet. Well, it didn't succeed! True, you killed my chauffeur. But when the car went into that canal I was thrown clear. You should have dived again, to make sure I was dead!”

“If you were attacked, it was by another Breguet" snapped Andre. "And I warn you, retract the accusations you just made or—”

“Retract?" snarled the other man, "I have just begun, Messieurs"— he swept his blazing eyes over Beeding and the rest of the Council— "I can prove what I say. I know now how our information reached Germany. I know who killed Lemoir and—"

Without warning, the lights in the chamber abruptly went out and the room was plunged into pitch blackness. Some one hurtled against Strange and knocked him down. In the same instant, there was a faint flash and a muffled grunting sound. A voice cried out in a gasping agony and there came the unmistakable sound of a body thudding to the floor.

Pandemonium filled the darkened Council chamber. Strange got to his knees, slipped again as some one fell over him in the darkness.

"Lights!" bawled Colonel Beeding.

"Somebody strike a match!"

In answer a small yellow flame flickered up — and Strange jerked back as he saw the body crumpled up beside him.

"Good Lord!" shrieked Beeding. "You've killed him."

Strange stood up. shaken, as Leeds rummaged through a drawer and found a candle. When the brighter glow lit up the room, a bullet-hole was plainly visible in D'Orcy's head. It was just above a bruised spot on his temple where the bandage had slipped.

"You killed him!" Beeding cried again.

"Grab the Captain, somebody!"

Torres, the Portuguese member, had already run to admit the guards. The two poilus now dashed into the chamber with guns drawn.

"Arrest these two!" shouted Beeding, jabbing a pudgy finger at Strange and Andre.

"Not so quickly, Colonel Beeding," interposed Major Smythe. "It looks bad, I must admit, but we must be sure—”

“Sure?" shrilled Beeding. "Didn't you see Strange down there by D'Orcy's body? It's plain as the nose on your face. _D'Orcy had the dope on him—so he switched off the lights and shot him. There's the gun, right where he dropped it."

An automatic with a Maxim silencer lay close to the dead man's shoulder. Ferrarri bent over it excitedly."Take notice, signores.. There is the golden paint on this weapon— the same as on the captain's hand."

Beeding looked triumphantly at the smear of gilt on the gun and at the damning marks on Strange's fingers.

“That settles it!" he barked conclusively, picking up the pistol and holding it by the middle of the barrel to avoid smudging the gilt marks.

"This will be Exhibit One—and it will send you before a firing squad, Captain Strange!"

CHAPTER V

CATACOMBS CLUE

Philip Strange paled. But his answer was cool. "You won't find my fingerprints on that gun."

Beeding held the pistol closer to his eyes.

"So that's what you were doing when Leeds lit the match— trying to smear your prints. Well, it won't work. I'm ready to swear I saw you doing it. And you're the only man in this room with gilt on his fingers.”

“Do you see any gilt on the light-switch?" Strange asked quickly. But one of the guards spoke before Beeding could reply.

"All of the lights went out; they were not turned off in this room alone.”

“You see?" cried Andre. "We had nothing to do with it.”

“You had accomplices outside," fumed Beeding. "They saw D'Orcy arrive and knew the jig was up, so they allowed time for him to get down here and then cut the main power line so you could break for it.”

“You are a fat-brained numbskull!" howled Andre. "These charges will make you the laughingstock of France.”

“They'll make me the Chief of G-2," Beeding flung back. "The whole thing's clear as day. You're the one who's been giving information to the Boche. You've been passing it on to Strange, and he's delivered it to Germany while pretending to be on some mission over the lines. You told him the places for the Gothas to bomb, and he's been guiding them with a Spad, which wouldn't be suspected so quickly by sound-rangers. And he used the luminous-skeleton idea so the Gotha pilots could see to follow him—probably had it tied with cords he could cut in a hurry if a searchlight was about to spot him. All he had to do was nose down and drop the skeleton— that's how the first one happened to fall into the Rue Grenelle”

“Then why," Strange said acidly, "didn't I drop the second one the same way?”

“Because It got tangled in your wing," Beeding retorted. "Andre saved you when D'Orcy caught you with it. The rest is obvious. As for the man stabbed at the wrecked house, he must have known something that would have endangered you; so you or this French runt pushed him against that wall so an accomplice could kill him."

Andre was almost dancing with rage. "'French runt!'" Andre lunged at Beeding, and only the guards' hasty action saved the portly Staff officer from a lusty crack on the nose.

"Now are you convinced?" Beeding wheezed at Smythe and the rest. "I've always suspected these two. Strange has pulled the wool over Colonel Jordan's eyes, blaming Karl von Zenden—Germany's 'Spy of a Thousand Faces'—when twice I had him red-handed. Swore von Zenden made up like him—yet half the time Strange himself was probably impersonating Allied officers to get information for Germany. Once I caught him made up as the Chief of American Air Service. But he wriggled out of it, said it was with the permission of Colonel Jordan for a certain mission."

There was a pause, in which Strange could sense the conviction of his and Andre's guilt growing upon others in the room. He looked down at D'Orcy's body, and a puzzled light came into his eyes, Andre misinterpreted his expression.

"Don't worry, mon ami! There is a murderer here—but I know the culprit is not you." Strange made a helpless gesture.

"All we can do is explain everything before a court of inquiry," he said.

"You mean a court-martial!" snorted Beeding as he motioned to the guards.

"March them upstairs. I'll go along and see that they're locked up at our M.P. headquarters. If I turned them over to the French," he added in an aside to Major Smythe and the others. "Andre would talk himself free in five minutes.”

“I think we had all better go along," said Smythe, "or there may be unpleasant repercussions from the French War Ministry. Our testimony will be required also."

Strange and Andre were marched out. The Council members followed, and the outer door was locked. At Smythe's order, relief guards were stationed there with instructions to admit no one until the Council returned with police officials to remove the corpse.

As they passed through the outer room to the gas-lock, Strange gave Andre a sidewise glance. Their eyes met, and the G-2 ace could see that the little major was puzzled. But he knew that he was also on his guard, ready for whatever action was indicated.

Beeding strode ahead, importantly holding the silenced automatic. Strange watched him a moment, then his thoughts went swiftly back to the Council chamber as the group began to mount the spiral stairs. That bullet-hole . . . . there was something wrong about it. He wished now he had been able to examine D'Orcy's body.

The lights were still out, and one of the guards illuminated the way with a flashlight. They came to the top of the stairs, and after a brief explanation to the astonished officer they started through the doorway to the courtyard.

Three men were approaching the entrance from the direction of the main gate, and just before Andre's guard switched off the flashlight Strange recognised one of the newcomers as Lieutenant Bayard. He gave Andre a swift nudge, and the little major burst out with a furious command.

"Bayard! Help me with these prisoners!"

Bayard and his men sprang forward, and in the same instant Strange whirled and snatched the automatic Beeding so gingerly held. His guard leaped after him, but strange ducked and the man caromed off him into the fat Staff officer. Bayard had seized Andre's guard, not recognising his uniform in the darkness. Andre wrenched the flashlight from the poilu's grasp, switched it on and flicked the beam over the group in the doorway, too fast for faces to be identified by Bayard's men.

"There they are!" he shouted.

"Don't shoot —drive them back!”

“Wait! Listen!" Beading croaked, trying to get his breath. "We're not the ones—"

Strange charged past the guard Bayard had collared and whirled Andre around toward the rear wall.

"Better put out that light!" he whispered tensely. "They'll be wise to us in a few seconds."

He caught Andre's arm and dashed for the wall, with the little major's feet hardly touching the ground. Behind them the tumult increased, as the guards at the gate and the men inside the door plunged into the fray.

"This way—not toward that wall-gate!" Strange muttered into Andre's ear. "Here, I'll give you a hand. We've got to go over the wall."

The guards at the chained gate had evidently raced to investigate the excitement, for no one appeared as Strange boosted Andre onto the wall. Shoving the gun into his pocket, Strange now crouched and sprang upward. He clutched the top of the wall, was half-way over when lights stabbed frantically around the courtyard.

"There they go!" cried Smythe's voice.

A gun roared, and a piece of brick flew from the top of the wall. Strange let go, dropped down beside Andre.

"To the left!" he rapped. "Keep close to me."

They ran through the blackness of the alley for about two hundred feet, then Strange led the way into a narrower passage, which intersected the alley.

"Where are you going?" gasped Andre.

"Doorway—just ahead," Strange tossed over his shoulder. "Hurry! Somebody's already over that wall."

Lights were probing through the first alley as his fumbling hands found a small wooden door set snugly in the wall on the right. He thrust his shoulder against it and it squeaked open. Andre jumped in after him. and he shoved the door closed. They had emerged in another courtyard, smaller than the first and surrounded by gloomy buildings.

"Turn on your flash for a second," Strange whispered.

Andre obeyed, and the G-2 ace looked around hastily until he saw a rusty man-hole in the centre of the court.

"All right, switch it off," he said.

'Nom d'un nom!" exclaimed Andre, as he followed Strange to the man-hole. "It is madness to go down in there—you might tumble into a sewer.

"No," said Strange. "I happen to know every inch of the way. Climb in—the bottom's only about five feet down."

He lifted the round iron cover, waited until the protesting Frenchman had dropped inside. Taking out his handkerchief, he wiped a trace of luminous gilt that had rubbed off on the cover, then jumped down beside Andre and lowered the cover over them.

"Hold your hand over the flashlight lens and switch on the light," he told the little major. Andre did so, and crawled along a few yards until the passage dipped steeply into blackness.

"Where does this lead?" he demanded. "To an old hide-out of mine," said Strange. "We'll be safe there until we can get ready for the next move.”

“Morbleu!" Andre said feelingly. "I would almost rather hide in a graveyard."

Strange laughed, a bit grimly.

"If we don't work fast, we will be hidden in one—permanently.”

“Pouf!" said the Frenchman. "No court-martial would ever believe that fat imbecile.”

“Smythe and the rest believed him," replied Strange. "Many a man has been hanged—or shot—on less conclusive circumstantial evidence. The case is too strong, Andre. That's why I signaled you to be ready for a break.”

“Well, did I not act swiftly? I was about to shout to Bayard even before you nudged me.”

“I didn't intend that sudden action," grinned Strange. "I was hoping you'd manoeuvre it so that Bayard would take charge of us, as senior French officer with police powers. But anyway, we're free.”

“And by this time branded as traitors with the alarm going out all over Paris," mourned Andre. "We can never clear ourselves now.”

“We have a fifty-fifty chance," said Strange. "I may be mad, but I think I'm beginning to see a little daylight.”

“And I think we will probably never see it again," retorted Andre, gazing down the gloomy tunnel. "What is this place?”

“An inspection passage, leading to one of the old sewers," Strange explained. "Here, give me the light. I'll show you the way."

He crawled ahead to where a number of iron rungs were visible. They afforded a hold in the steep descent. Thirty feet down, Strange paused.

"Be careful along here. Two of these rungs have loosened a trifle.”

“Why, in the name of all that is holy, did you ever have to hide in such a place?" exclaimed Andre.

"Because it was the only one left," said Strange. "Do you remember a time when I was reported dead—in 1917?”

“Oui, most certainly! You were missing for more than two months— it was after the Kaiser had ordered the Nachrichtendienst to capture or kill you.”

“I was only one of several he included," Strange said. "But Boche agents did make it too hot for me. I escaped by the skin of my teeth two or three times. But when a number of G-2 agents were taken for me and suffered death in my place, Colonel Jordan agreed that I should disappear, letting the Germans think they had finished me. From a previous case, I knew the Apaches had hideouts under Paris, and I found one of my own, not far from the sewer at the bottom of this passage. Jordan arranged it so I received money, uniforms, and make-up supplies at an address in the Latin Quarter, where I posed as a crippled art student for a while. By night, I brought what I needed to this hiding-place, including a wireless receiver on which I caught special-code instructions from Jordan. From this base, I went on several missions and played various roles during that period—until our counter-espionage rounded up the assassins the Nachrichtendienst had planted in France."

As he explained, Strange had been carefully making his way downward, and now he stood at the bottom of the ladder on a ledge beside the old sewer. A dark and filthy current flowed slowly past, giving off an unpleasant stench.

"Sacre nom, what a smell!" ejaculated Andre. His voice boomed from the arched roof of the sewer, and Strange hurriedly cautioned him.

"You'll have to whisper. Sounds carry a long way in these sewers, and running into a bunch of Apaches wouldn't help us.”

“No self-respecting Apache would ever come near this place," said Andre, holding his nose in disgust. "Which way do we go now?”

“Along this ledge for about two hundred yards. There is a branch sewer, and the entrance to my 'old home' is a little way back from the junction.”

“And just what," queried Andre, as they started on, "do you expect to do after we get there?”

“Change our faces so we can move freely up in Paris. There is one man who will believe in us — Marshal Foch. We must reach him tonight.”

“You mean you have a solution for that murder?”

“No. Frankly, I'm up against a blank wall," said Strange. "But neither of us killed D'Orcy. That means it had to be one of those five. Yet I can't fit any of them with it. Now if it were possible to believe that D'Orcy killed himself for some wild reason—”

“Not he," said Andre. "D'Orcy would be the last to commit suicide, even to avenge himself for a fancied wrong by sending some one to a firing squad.”

“Well, we shall soon be where we can stop and think calmly." Strange pointed the flashlight ahead as the sewer curved. "We are almost to the branch, and then—" He paused. "By the way, be prepared to see a few bones and some skulls when we get there. This place of mine is part of the old catacombs—obviously one of the forgotten series of vaults since no one seems ever to have come there.”

“Pardieu!" Andre exclaimed, stopping short. "What's the matter?" said Strange. "Not afraid of a few old skulls after tonight's business?”

“Name of an imbecile!" muttered the little major. "How could I have failed to remember? Strange, I know now where I saw that old one who was stabbed. His name was Lamotte. He was formerly a guide at the catacombs to which tourists are admitted. He was arrested for secretly selling souvenirs to the tourists. He was accused of meeting them after they left the Catacombs and selling them skulls—even whole skeletons if they could pay the price. But it was never proved that he stole them from the Catacombs. Thus the charges were dropped, though he was dismissed."

A gleam of excitement had come into Strange's eyes. "Good Lord, if we'd only known this before! It explains all the skeleton business!”

“Yes, I can see something very peculiar—but it is all too vague," said Andre.

"Look," said Strange, "this man Lamotte was getting his skeletons from somewhere—but not the known catacombs. What if he—or some one else—had discovered these vaults that everyone had forgotten? What more natural idea than to sell bones and skeletons to tourists—and to get hold of a catacombs' guide to tout them for him, assuming it wasn't Lamotte who discovered the source?”

“Bon Dieu!" cried Andre. "I begin to see now. This Lamotte was there at the wrecked house to collect something he said was his. The man who discovered the forgotten catacombs must have betrayed the old man— refused to divide the profits, and Lamotte hurried there when he heard of the explosion, hoping to steal money he thought perhaps to be hidden there.”

“Exactly," said Strange. "Some one—either Madame d'Aubreil or her step-son, and probably the former— used the basement of that house as a place to store the bones taken from the old catacombs. Lamotte must have taken customers there, or at least gone there for the skeletons.”

“Then there never was a skeleton dropped in the Rue Grenelle tonight!”

“No, it was one already in the house—they must have tricked up their goods with luminous paint to keep them from deteriorating and to make them appeal to buyers.”

“To think that people would wish to buy the bones of the dead!" grimaced Andre. "There are certain people to whom such gruesome things appeal," said Strange. "And they're the very type who glory in visits to catacombs. But that's not important. Do you see where all this leads us?”

“Yes—and no," replied Andre. "There must be something connected with that old house which some one wishes not to be known.”

“That's it," said Strange. "There was an explosion—most likely from inside the house, since no one heard a bomb or a shell falling. It wrecked the place and blew part of an old skeleton out in plain view—undoubtedly one Madame d'Aubreil or somebody had wired up and painted years ago and hadn't sold. An explanation had to be forthcoming in a hurry, or the police would investigate— therefore, the falling skeleton story was invented, and parts of a helmet and goggles were tossed in for an air angle. And to clinch it arrangements were made actually to drop another skeleton into Paris as soon as possible. That was the one I ran into. It explains the paint not having dried.”

“But not how your skeleton was racing along through the air with you—or where it came from," interjected Andre. "Also, was it really Lemoir's skeleton?”

“No, I think that was another false lead," said Strange. "If I'd have had time to examine that arm carefully, I think it would have proved to be from an old skeleton. It was painted hastily, and a pair of goggles was fastened onto it to fit in with the first business. Lemoir's tag was a good touch—tying it up with a missing man. But I'm afraid he has met with foul play, even if it wasn't his skeleton.”

“But we still do riot know how the skeleton was flying," persisted the little Frenchman. "It must have been taken up in a plane—that's the only logical answer. If it were tossed over the side from a cockpit, it would have seemed to come from nowhere, providing the ship were above me.”

“But you would have seen a plane," objected Andre. "Not if the exhaust stacks were shielded. It was so dark that—" Strange snapped his fingers. "I have it! That black Breguet! It had masked stacks, and even with the searchlights on I didn't see it until the last second." Andre started. "And there was a black Breguet just like that which took off from the Fifth Defence Escadrille. It was the ship in which D'Orcy sent his agent with one of Jacques' pilots. Jacques told me— Nom de Dieu, what if it was not an agent, but a skeleton bundled up and put in that plane?”

“That would mean Jacques and D'Orcy were both in on it," muttered Strange. He had stopped at the junction of the sewers and was gazing unseeingly into the dark waters. "D'Orcy was killed—but he still could have been involved. I don't think Jacques is crooked. If there were a substitution of the skeleton for the passengers—or if the passenger carried the skeleton with him, which is more likely—it must have been done after the ship taxied away from the line. D'Orcy could have had some one waiting out there to hand over the skeleton in the dark, and it wouldn't have taken more than a few seconds.”

“It is the solution!" exclaimed Andre. "I was wrong, and D'Orcy's hatred for the Boche must have been a pretence. He was only pretending to send an agent across—and as for the skeleton's flying, it could have been lowered by a looped rope, or perhaps D'Orcy's man was holding onto it while his pilot was trying to shake you off, and then in desperation he had to let it go before he wished, when the searchlights went on.”

“I think you've hit it," said Strange. "And D'Orcy jumped into the other Breguet with you, hoping to cover up any slip. Later he must've been afraid we'd figure things out, so he staged that act at the Pool, pretending he'd been fired on—to get us under suspicion and locked up where we couldn't talk.”

“Yes, but then why was he shot— and who did it?”

“There's something queer about that. It's been knocking at the back of my mind ever since I saw the bullet-hole. S o m e t h i n g different about—"

The G-2 Ace broke off, triumph, then consternation, racing into his face. "Andre, I've been blind as a bat! Come on—we may be in time yet!”

“But what—where are we going!”

“To that old house. It must lead from there—we should be able to find it by following one of these branch sewers.”

“What are you talking about?" insisted Andre. "What leads from__"

He stopped as Strange hurriedly turned off the light. The G-2 Ace gripped his arm.

"Listen! Some one's coming down the other branch of the sewer!"

A mumbling of voices became increasingly audible, interspersed with a steady creak of oars. In another moment, a faint glow appeared from the blackness of the connecting sewer. Strange jumped in spite of himself. For the glow came from the luminous figure of a skeleton sprawled over the prow of a boat!

CHAPTER VI

SPY DEN

They flattened themselves against the curved side of the sewer, thirty feet from the junction. The boat slowed as it came into the main sewer.

"Back along the ledge!" Strange whispered in Andre's ear. "Don't make any noise."

A form now partly blotted out the skeleton. It was a man who was peering into the shadows.

"Sehr gut," the fellow said gruffly, "this is the one. We will be there in a minute or two.”

“I hope so," growled another voice in German. "My back is almost broken. How about you, Hans?”

“Ja," said a third man, as the oars creaked again, "if we have to make that trip once more, I think I get one of those little motors to fasten on the stern”

“And go pop-popping along until some gendarme hears it through a street-drain and investigates,' said the man in the bow irritably. "Keep to the left, or you will hit the side.”

“Then use your light," said the one called Hans. "Herr Bones is fading.”

“Half of the paint is rubbed off where it caught on the Spad's wires," replied the bow-man. He looked up and down the main sewer, switched on a small electric lantern hung on the prow. Strange held his breath, but the boat kept straight ahead and he and Andre remained in the gloom.

"Why does his Excellenz want that skeleton again?" asked the third German.

"To plant it as was first intended," grunted the bow-man.

"It's so no-one will suspect the truth about the old d'Aubreil house. It would have been all right had not that verdammt American come along and interfered. Now we will have to stage another act and pretend we saw it fall.”

“Are you sure no one saw you and Friedrich around the Spad?" Hans said anxiously.

"Will you stop worrying about that?" returned the bow-man. "I told you three times they had put the plane in a hangar and we had no trouble. You could not have hired a Frenchman to go near it after they heard it was that pilot's skeleton."

The voices were becoming inaudible, and Strange whispered for Andre to follow him along the ledge. When he stole around the turn into the branch sewer he beard Hans speak plaintively.

"It is all right for you to laugh, but somebody might follow us. What about the French police agent who came through this same sewer from the escadrille? He found the passage to the d'Aubreil basement—”

“Sacre bleu" Andre hissed into Strange's ear. "That must have been Sergeant Douville.”

“The schwein won't bother us any more," said the bow-man with a dour chuckle, "I will never forget his face when I tossed his own grenade back at him.”

“And I won't forget how your face looked when I came back from lying to that first policeman," Hans said maliciously. "Even in the dark I could see it—whiter than the skeleton's.”

“Who wouldn't be white, caught under that wreckage and the police so close? At least you could run, and the Oberst was safe in the passage after sending you out.”

“It is a bad business, all of it," grumbled the third spy. "If I had it to do again, I would not volunteer—even for double the bonus money.”

“We won't have to wait much longer," said the bow-man. "Because of all this, his excellenz said we would have to strike tonight. If it goes as planned, we shall be back in the Fatherland by dawn.”

“Himmel" exclaimed Hans. "Think of it—a month's furlough with all the money one could need. My back feels better already.”

“And there's the niche," said the bow-man. The boat swung in toward a spot where the old masonry had caved in, creating a miniature harbour about three times the size of the boat. Strange and Andre stretched themselves flat on the ledge, watched as the boat was secured. Hans and the third Boche lifted out the skeleton, and the bow-man made his way ahead on the ledge. He had almost reached a curve in the sewer when he halted and set down his lantern so that it shone on the wall. A rusty spike protruded from between two bricks at the height of his head. He counted down ten bricks, then ten to the right, and shoved with both hands.

A section the size of a narrow door gave at his touch, opening inward. At once, a guttural voice mumbled something from the blackness within.

"Herr Rueller and party," responded the spy who seemed in charge. He picked up his lantern, and Strange saw a thick-set man standing just inside, blinking in the light. Beyond was a passage which seemed to twist away to the left. The three spies entered, Hans and his oar-mate bearing the skeleton. Then the door closed with a click. Andre instantly jumped to his feet.

"Vite!" he said, spinning around in the direction from which they had come. "We shall have to move swiftly.”

“You're going the wrong way," said Strange. "But no! I am going to summon help—so that we can raid that spy-den.”

“You'd be arrested the minute you were recognised," Strange told him. "Unless you could reach Marshal Foch. Probably no one would believe your story—or they would think you were merely double-crossing the spies to save your skin.”

“But what are we going to do?" groaned Andre. "Go in there after them and find enough evidence to clear ourselves and wreck the whole scheme.”

“It is suicide," mourned Andre. "But at least we will die fighting. Hurry, before they get away from us.”

“I want them to get ahead," whispered Strange. "If anyone hears that guard when we tackle him, we're licked at the start.”

“Then you know the way? It is the hiding-place you used?”

“No, I never suspected there was another entry. This must be the one used by Malotte and Madame d'Aubreil, or whoever robbed the old catacombs. The entrance I knew is a little farther on and nothing elaborate like that one. It goes into the second level of the catacombs, and there's another exit—a pivoted stone that opens into the same kind of inspection passage which brought us down here. It leads to a manhole near the intersection of the Rue de Bac and the Boulevard Raspail. Maybe these Germans have stumbled onto that connection, too.”

“If ever I get out of this muddle," Andre said in a low voice, "I shall investigate all the sewers in Paris. I knew the city was honeycombed with them, but I never thought I would need to know them like avenues.”

“I thought I knew most of them," replied Strange, also in an undertone. He was still watching the dark wall where the door had closed. "But I never had cause to follow that branch very far. It obviously goes out to the southeast, under Bercy, and there must be an opening close to the escadrille.”

“There is," muttered Andre. "At least there is a culvert over which one drives, and I suppose there is a sewer connection there. But I never dreamed of its being used by spies.”

“It makes clear the disappearance of Lemoir and the others," said Strange. "They were probably seized in about the same way that the skeleton was put into the Breguet tonight, and either flown across the lines as prisoners—or taken into the sewer.”

“And killed" grated Andre. "Oui, that is the most likely thing. They could strip the bodies and let them drift out into the Seine, or sink them with weights. It would explain how they had Lemoir's tag so handy— and that of Benet, which was dropped to mislead us at the d'Aubreil house."

Strange rose to his feet, with a cautioning whisper.

"I think they've gone far enough so we can risk it. Be ready to switch on your flashlight the instant the door opens, then jump to one side after you blind the man on guard."

They tiptoed along the ledge. Strange took the silencer-fitted automatic from his pocket, counted the cartridges in the magazine. They crossed the niche, using the boat as a bridge.

Andre flashed on the light as they came to the spike, and Strange quickly found the right brick. Stepping as far to one side as possible, he raised the gun, then shoved the brick with his other hand.

With a crunch, the brick moved into its recess, and the hidden door swung on well-oiled hinges. Andre's light was pointed straight into the opening, and with dismay Strange saw that there were now two guards, one evidently having just come to relieve the other.

"Was ist?" demanded the new man, his hand on the gun at his hip.

"it is Herr—" began Andre. then he jumped to the right as Strange leaped. The butt of the automatic thudded on the German's head and he fell without a sound. The thickset man sprang back with a yell. Strange lunged, drove the spy against the side of the passage.

"Hilfe!" bawled the man, the word dying to a gurgle as Strange's free hand closed on his throat. Andre had charged in after the G-2 Ace, dropping his flashlight to seize the spy's gun-hand. With swift efficiency, the little major cracked the spy's own pistol against his temple, and Strange felt the German's strength flow out of him. He let the inert form slump to the ground, scooped up the flashlight and turned it off. For almost a minute, he and Andre stood listening tensely in the darkness, but there was no sound to indicate that the spy's alarm had been heard. Closing the door, which proved to be of wood painted on the outside to resemble the sewer wall, Strange cautiously switched on the light, holding it under his unbuttoned uniform blouse so that only a faint glow shone.

"I think we're safe for the moment," he said to Andre. "But we'd better tie up these two before we go ahead."

In five minutes, the Germans were gagged, and bound with their own belts and the Sam Browne which Strange donated for the purpose. Keeping the light shielded, the G-2 ace led the way through the passage, which was supported at intervals by old half-rotted shoring.

"Poor Douville must have come this way," muttered Andre. "If he had only communicated his suspicions to me, He might be alive now.”

“He probably discovered something he had to follow up at once," Strange replied in an undertone. He looked warily around a turn in the tunnel, went on. There was another turn at right angles, then a fork was visible.

"Now which way?" whispered Andre.

"Let's try the right passage," said Strange. "And we'll have to hurry— this battery is getting weak."

The right-hand passage went straight as an arrow for about a hundred and fifty feet, then turned left and inclined sharply upward. Strange had not gone ten feet when be saw a wide, irregular hole, partly blocked by an old trunk and a heavy beam which had fallen down at an angle. He went closer, saw that be was looking at the cellar of a house into which most of the upper floor had fallen. A box of yellowed skulls lay under a work-bench, near a larger box which had been broken, scattering bones of various sizes and shapes across the floor.

"Pardieu! It is the basement of the d'Aubreil house!" exclaimed Andre.

"Not so loud," whispered Strange. "The police will hear you."

Vague sounds could be heard from above the tangle of wreckage which filled the basement. Strange backed into the passage.

"We'll have to return to the fork. Try to figure out the angles and distances from here so we can keep track of where we are.”

“Tres bien," said Andre. He was silent a while as he followed the taller man. "I wonder if that building was the main headquarters for the spies. It was supposed to be empty, and it would have made a good place.”

“Probably their living quarters," replied Strange, "but I've a hunch we'll find the business office down at the end of that other tunnel."

He increased his pace to a run as the light became dimmer and dimmer, and the little major panted in the effort to keep up with him. When they came to the fork, Strange turned suddenly.

"I've changed my mind—we'd better divide forces. We've learned enough to act on. anyway.

'But how?" said Andre. "I'll go into this passage. You go back and change clothes with one of those spies we knocked out—trousers and coat are all you need. Rub some dirt on your face and then hurry to the courtyard where we entered the manhole. You can find a cheap hotel with a telephone about two blocks south,”

“I can locate a telephone, yes. But what then?”

“Call the War Ministry—disguise your voice and pretend you're sergeant Douville. Tell some one who can get quick action that there's a nest of German spies under Paris, that one entrance to their base is in the basement of the d'Aubreil house and the other is in the cloakroom of the Council chamber at the Intelligence Pool." Andre jumped as though he had been stung. "Mon Dieu! Do you mean these devils have tunnelled into the Intelligence Pool?”

“Positive. I should have guessed it before, but things happened too fast.”

“One moment," Andre said tensely, "I must be sure you are right! For if this is true it means—”

“I know what it means But it's the only solution that explains everything. Did you notice the bullet-hole in D'Orcy's head?”

“Oui, but what of it?”

“It was at a point where the bandage had been when we first saw—or thought we saw—D'Orcy come in. Of course, the bandage could have slipped before the shot. But there was also a purple bruise near that bullet-hole—and it was not the same as the bruise I noticed before the lights went out.”

“What are you talking about?" said Andre, bewildered. "Simply this; The man who came raging into the council room was not the man we found dead on the floor.”

“Not the man—then who . . .?”

“Beeding accidentally gave us the key," Strange answered. "It should have instantly been apparent when he mentioned Karl von Zenden."

"Von Zenden?" said Andre amazed. "Nom d'un cochon, I see it! What a fool I am! It was that fiend all the time—”

“A somewhat discourteous way to speak of your host, monsieur," a mocking voice suddenly broke in. Strange whirled, then froze with his gun half-lifted. For a face like the face of Victor D'Orcy was smiling at him across a Luger.

CHAPTER VII

SPY OF A THOUSAND FACES

For a fraction of a second, Strange weighed the chances of striking out at the Luger and firing as he did. Then, in the shadows behind the man, he saw three other figures and caught the glint of metal.

"It seems that you win, von Zenden," he said coolly.

The German impersonator bowed without taking his eyes from Strange's face.

"A pleasure long denied me, my dear captain. But we are short on time. So if you and Major Andre will just drop your weapons and step back, we can be on our way."

Strange obeyed silently, Andre with a Gallic oath muttered under his breath. Two of von Zenden's men picked up the guns and stepped around behind the captives. The others divided, one going toward the house, the other toward the sewer.

"If you will follow me, I shall be happy to act as your guide," the Prussian said silkily, "though I assume from what I overheard that you have an idea of your destination.”

“A cave near the intelligence Pool, naturally," said Strange, avoiding mention of the forgotten catacombs. He went on calmly, hoping to keep the Prussian in the same sardonic mood. "It was fast thinking to stage that 'murder'-act in the dark and have your men substitute the corpse of the real D'Orcy.”

“It will do you no good to flatter me this time," von Zenden returned. "I recall what happened at our last meeting. As for fast thinking, you seem to have gone into a decline. If you noticed the difference in faces, you should have known there was a substitution and instantly guessed the existence of our secret door to the cloakroom or the Council chamber.”

“Stupid of me," admitted Strange, "but I was befuddled by the accusation of murder.”

“It was indeed fortunate that we had had no time to dispose of D'Orcy's body," said the Prussian. "If it hadn't been for that meddling French sergeant who cornered three of us in the Rue Grenelle house and tried to blow us up with a grenade, D'Orcy would have been at the bottom of a sewer—like Lemoir and the others when we needed their planes to send agents back to Germany.”

“So the sewer is to be our final resting-place," Strange observed, trying to match von Zenden's amiable cold-bloodedness.

The impersonator laughed softly. "Oh no, mein Freund, I have other plans for you and your estimable comrade. I admit I ordered your sudden death earlier this evening, after tapping the wire to Captain Jacques' office, but I regretted the necessity very much. Now that you have so kindly placed yourselves in my hands I am glad you escaped from that trap and also from that overstuffed dumkopf, Beeding. It will make the final act in our little play nothing short of brilliant."

Von Zenden now called a stop before a mouldy-looking door which, when opened at his signal, proved to be backed with steel plate. A black-browed, fierce-looking man in Apache garb lowered the pistol he had snatched up.

"Did you find anything wrong, Excellenz?" the man began, then broke off as he saw the prisoners.

"Ja, Rueller." said the Prussian, "we found why Greining did not return—and also we found our very dear friends, Captain Strange and Major Andre."

"Leiber Gott!" Rueller burst out. "If the police were so close after them, as you said, then we will be trapped.”

“But I overheard part of their conversation." responded the impersonator, "and it is quite evident they eluded the police. The Frenchman probably knows the sewers fairly well and thought of them as a natural place of concealment. They must have seen you and the others returning in the boat—then followed you after seeing you open the sewer-door."

Strange hid his interest, but he was listening carefully. They had come into the lower level of the old catacombs. He had initially supposed that von Zenden had discovered his former hiding-place and its contents, but apparently it had not been found.

"Where are Friedrich and Hans?" asked Rueller, with the door half-closed. "Friedrlch has gone to see what happened to Greining, and Hans is going to make sure that none of the wreckage above that basement has shifted so that the passage can be seen. The police left a man inside the fence they erected, and he might be poking around with a torch to see if he could pick up a few trinkets here and there."

Rueller closed and barred the door.

"I hope we will be out of here soon, Excellenz," he said uneasily.

"Within two hours at the most," replied von Zenden.

"What about Herr Bones?" inquired the black-browed German. "Do you still wish to have him planted up on one of the avenues?”

“No, the whole area is swarming with police hunting for our two guests. It would be dangerous—and as events have turned out, unnecessary.

Von Zenden strode on, and the two captives were prodded ahead by the armed spies behind them. The tunnel in which the steel-backed door had been built abruptly widened, and steps cut in rock led down several feet to the floor of the catacombs. The niches along the wall, formerly filled with skeletons or heaped with bones as Strange recalled, were now packed with dirt brought from a round opening in the wall, seventy feet or so beyond. He knew at once that this must be the tunnel the spies had dug to reach the Intelligence Pool, and a hurried estimate of the amount of dirt indicated that it was only a short passage.

The scene before him was one of amazing contrasts. From the second and third tiers, yellowed bones and skulls shone in the flickering light of candles set at close intervals about the room. Through passageways to right and left, other catacombs' rooms could dimly be seen, with their gruesome relics.

Seated at a large table in the first room, six men in the garb of Apaches were writing feverishly from three red books opened before them, each man striving to finish his side by the time the other man was ready to turn the page. At another table, another group of men was as busily making copies of notes on yellow scratch paper.

"Sacre Dieu!" groaned Andre. "They have stolen the key-books of the whole Allied Intelligence System!"

Two or three of the spies jumped up, and the others cast startled glances at the captives.

"Pay no attention to these two!" von Zenden snapped. "Keep writing! When you finish, you leave—for Germany!"

The spies resumed their work at furious speed. The Prussian smiled at Strange and Andre.

"Now, perhaps you understand why we were so desperate about covering up the secret of the d'Aubreil house. We could have burst into that soundproof council room through our secret door and have taken these books by force. We could have killed everyone in the room and escaped.

We could have reached the Fifth Defence Escadrille and seized planes there according to plan—but the theft of the books and other information would have been known within a few hours. This way, the books, the scratch paper, the new offensive map which we have also copied—all these will be back in the council-room before anyone misses them. We shall not only be able to seize every Allied spy now in Germany, but through the communication routes described we can send back false information for your General Staff to use in moving their armies around for this drive."

For a moment Strange forgot his own peril in the horror which his mind had conjured at von Zenden's words. Allied agents—many of them personal friends—would die by hundreds over in Germany, and that would be but the beginning. On the basis of false information, Allied armies, and especially the A.E.F., would be trapped in the great Argonne offensive. Every ammunition depot, gun emplacement, headquarters, and other strategic points, would be known to the German forces. France would run red with American blood.

Andre's furious voice brought him back to the present.

"You'll be caught like rats! Even now they may be in that council room. They'll guess the truth when they find the books gone. They'll tear down the walls and find the secret entrance to this place —”

“Quiet, you little fool!' snarled von Zenden.

"It won't help to yell— no one can hear you up there. And no one will visit that room for at least two hours. No one has the keys or the authority to enter, except the Council members—as you well know. And the Council is at the War Ministry, awaiting Marshal Foch's arrival from Senlis."

Andre fell grimly silent, and for an instant there was only the feverish scratching of the spies' pencils. Then one of the two guards spoke to von Zenden.

'What shall we do with the prisoners, Excellenz?”

“Tie them up. No, not over there—" as the guards started to shove the captives toward a corner where rope and cords were coiled beside some boxes of hand grenades and candles. "I have had one bomb thrown at me tonight—that is enough."

Strange looked sidewise at the box, but the Boche behind him jabbed him roughly with his pistol.

"Get over to that other doorway! 'Schnell!"'

Strange glumly obeyed, hands raised, and Andre followed, stood beside him only while one spy covered them and the other went back for rope. Von Zenden stood watching, an ironic smile on his made-up face. Suddenly the smile altered, and he wheeled as a frantic voice sounded from the passage to the steel-backed door.

"Herr Oberst! Mein Gott, we are lost!"

It was Rueller, his eyes protruding, his face ashen. Behind him panted another spy, with sweat running down his cheeks.

"Speak!" raged the Prussian. "What's happened?”

“The d'Aubreil house—they're digging into the wreckage! Police with lights and guns!" the man with Rueller cried hoarsely. "I heard them talking—the one named Bayard ordered it—he found out the name of Madame d'Aubreil's stepson was Santos and he's identified Lamotte.”

“Zum Teufel!" snarled von Zenden. "I never dreamed that stupid-looking swine could figure out the truth.”

“He knows about Lamotte's selling the skeletons, and he must have guessed the rest," moaned the other man. "But that isn't the worst. I heard him order some one to call the War Ministry and have the Council and Marshal Foch come to the Intelligence Pool. Foch flew from Senlis with Captain Raimond, his personal pilot, and landed in the Boulevard Raspail."

Von Zenden whirled to the frightened spies, who had now leaped to their feet and were listening open-mouthed.

"There's no time now to finish copying the books. Put them together—these papers with them and the offensive map. Tie them in one bundle and I'll get them to Germany!”

“But what of us?" cried Rueller.

"You'll escape as planned!" snapped the Prussian. He ran into the room on the right, reappeared with a make-up kit. Snatching at an alcohol-saturated cloth, he swiftly wiped the greaseless paints and shadows from his face. The features of D'Orcy vanished, and the coldly sardonic countenance of the real von Zenden emerged. 'Put a time-grenade in the passage to the Pool—set it for five minutes. Bayard must suspect about the secret door, or he wouldn't have sent that word to the Ministry. I'll be out of here in three minutes made up as Captain Raimond. I'll go out to the sewer and up through the third manhole—the one that opens in the alley near the Rue Varennes. There are three Nieuports secured within a short distance. The mechanics guarding them will never question an order they think is from Foch's aide. I'll take one of the Nieuports and make for Germany. There's no time to warn the men who painted the luminous crosses to guide the Gothas. They'll have to shift for themselves."

The impersonator had propped up his make-up kit on one of the tables and was now seated before it altering his features with fast-moving fingers. Snipping bits of black crepe hair into the proper lengths, he went on crisply:

"Take a grenade, each of you—the high-explosive, not gas. You'll have no time for gas-masks when you reach the escadrille. Rueller, you'll be in charge—wait till all three boats are at the culvert exit, then lead the men out silently. Use your grenades on the officers' quarters first, then the mechanics. A quick surprise, and the few who are left will flee. You'll have enough planes to carry all of you back to the Fatherland.”

“We are short a pilot!" cried one of the spies.

"Then let one man ride a wing," snapped von Zenden. He swept a spirit-gum brush across his upper lip, deftly worked the bits of crepe hair into a close-cropped moustache. "Hans, take two men and set time-grenades in the tunnel to the basement of that house. Put the first as close as you can get and set it for three minutes; allow five minutes for the others. That will give us time to get to the sewer. We'll blow that passage, too, and it will be hours before they can dig through. Even then, they probably won't suspect the connection with the escadrille for a while, and we'll be in Germany long before."

Most of the spies began to crowd through the entrance to the sewer passage, but the captives' guards, though obviously frightened, stood their ground. Rueller shot a tense look at Andre and Strange.

"What of these prisoners, Excellenz?"

Von Zenden replied inaudibly, took a final look into his kit mirror and jumped up. Through his artistry of make-up, his face seemed to have broadened. His cheeks were plump from cleverly-fitted overlays and under the clipped moustache his whitened teeth shone. His darkened brows were arched exactly as Strange remembered Captain Raimond's, and his expression showed the same suave poise as that of Marshal Foch's dapper air-aide.

"My other French tunic!" he said swiftly to Rueller. "I'll have to change the insignia on the way."

Rueller dashed into the room on the right, came back with blue uniform coat and a French officer's cap.

"Herr Oberst!" one of the guards said hoarsely. "it is only one minute until the first grenade will explode!"

Von Zenden jammed the cap on his head. "Back to the exit!" he ordered. "Keep the prisoners covered.”

“Strange!" screamed Andre. "This monster means to bury us alive!"

Von Zenden's eyes gleamed from his made-up face.

"Goodbye, my friends! I shall miss you."

He turned and ran up the steps to the steel-backed door, which Rueller was holding open. Andre tore himself free of Strange's restraining hand, charged after the Prussian. At von Zenden's shout, the guards sprang through the opening. The impersonator leaped after them—and the door closed with a dull metallic thud.

When Strange caught up with Andre, the little major was frenziedly hammering his fists against the steel plates, The G-2 ace hauled him back by main force.

"Come on, or you'll be killed!"

The words were hardly out of his mouth when an explosion shook the ground, and a geyser of smoke and dust shot from the passage to the Intelligence Pool. Strange caught Andre's wrist, dragged him up the crude steps to the second tier of the catacombs. Another explosion made the ground quiver, and one section of the wall fell, carrying a row of crypts with it. Some of the gas grenades went off and Strange fought on through the acrid fumes and blinding smoke, feeling his way until his groping hand touched the curved stone of an arched doorway.

"We must go back!" Andre cried. "There may be air along the floor— it's our only chance!"

"We're not dead yet!" Strange said hoarsely. He pulled Andre along, fumbling, counting the stones from the arch. This was the one! But it had been almost a year....The stone might have wedged....

The wall seemed to fall away at his desperate push, as the pivoted stone slowly rotated.

"Andre, I've found the old exit!" he shouted. "We're saved!"

A draft of cool air blew back the smoke. He sucked a breath deep into his lungs, helped Andre through the wall and into the inspection passage.

"Thank the good God!" Andre gasped. "I thought we were finished."

Strange shoved the stone back into place. "We've got to stop von Zenden! Hang onto my sleeve and keep your head down."

Panting, bumping into turns in the passage, now and then falling over protruding bricks, they kept on until at last Strange stopped at the foot of a vertical iron ladder above which a spot of light showed.

"Where are we?" Andre asked breathlessly.

"At the Intersection of the Rue de Bac and the Boulevard Raspail. That spot is the centre of the manhole I told you about. There must be a light nearby.”

“But von Zenden went the other way—to the planes in the Rue Grenelle!”

“This was the quickest way to cut him off," panted Strange. "I'm going to try to grab one of the defence ships and bring him down. Keep the poilus from shooting at me, if you can."

He climbed the ladder, cautiously lifted the manhole cover an inch. Several flares and a floodlight had been lit. To his dismay, two long official cars stood within a hundred feet of the manhole, with officers and armed poilus standing around. His gaze swept the scene quickly, then be lowered the cover.

"Beeding and the rest of the Council are up there," be whispered. "They evidently came to meet Marshal Foch's ship, and their cars are inside the ropes.”

“Papa Foch will surely listen to me," said Andre.

"Do your best to explain in a hurry. I'm going to duck back of the cars—if we lose another minute, von Zenden may be gone. There's a blue Breguet closer than the Nieuports—”

“That is the Marshal's ship!" exclaimed Andre.

"I thought so. Its engine ought to be hot enough to kick over. Here I go!"

The iron cover clattered to one side and Strange leaped up into the boulevard. Amazement held poilus and officers paralysed for a second, but as he whirled to dash behind the cars, Beeding's voice rose shrilly.

"Seize that man! He's the murderer of Major D'Orcy!"

Strange sprinted around the wing of the blue Breguet. A gun blasted as he vaulted onto the step, and a bullet clipped the rear windscreen.

"Stop, you fool!" Strange saw Andre wrench a pistol from one of the officers, then run toward Marshal Foch.

"Kill him!" screeched Beeding. "He's trying to murder the Field-Marshall!"

A poilus fired wildly. Andre sprang around one of the cars, just as Strange flung himself into the front cockpit and snapped on the ignition switch. Another gun barked, and the little major despairingly dropped his pistol and dashed for the plane. Strange had seized the spark-advance knob, was jerking it back and forth. The Liberty coughed, then began to rev up.

Andre caught the side of the ship, pulled himself up into the rear pit. Behind him came a dozen pursuers, with Beeding and Smythe in the lead. Strange gunned the Liberty wide open. Hit by the air blast, the portly Staff Colonel went backward three steps, sat down with a jolt, and Smythe fell over him headlong. A flurry of dust from the street covered the two men as the Breguet lunged forward, but red flashes showed where pistols were blazing at the fugitives.

Strange saw a French pilot leap into a Nieuport pit and a mechanic run to the prop, as the two-seater thundered past. Across the boulevard, a Hotchkiss gun spurted flame, and tracers left a smouldering mark across the cowl. A searchlight went on, swung to follow the Breguet. Another machine-gun clattered fiercely as the ship roared past the intersection of the Rue Grenelle. Strange bent over the stick, shot a look at the air-speed meter, Suddenly Andre thumped him on the back.

"Von Zenden! The Nieuport!" he howled.

Its wheels off the pavement, a dun-colored Nieuport was darting out from the Rue Varennes, almost in the two-seater's path! Strange clamped his Vickers trips. The Nieuport zoomed wildly, and von Zenden threw a startled look over his shoulder. Strange pulled up in a grinding chandelle, his tracers barely missing the Prussian's tail. Another searchlight flashed from the top of a building, caught the two-seater broadside. A look of stupefaction crossed von Zenden's made-up face as he recognized Strange and Andre. With incredible speed, he hurled the Nieuport into a vertical bank. Strange tried to follow through, but the heavier ship overshot. Andre spun the tourelle, drove a burst from his twin-guns into the Nieuport's right wing.

Von Zenden madly reversed his bank to save his weakened wing. Strange swiftly crossed his controls, brought the stick back. The Prussian's ship was almost in his sights when another Nieuport plunged into the battle. It was the defense ship which had been started as the Breguet was taking off.

A stream of smoking bullets shot in diagonally, crashing Strange's cowl and tearing on through the tilted wings. Andre pounded out a furious answer, aiming dangerously close in the attempt to drive off his countryman. Von Zenden, abruptly freed from attack, zoomed to escape.

Though the defence pilot's guns were tearing the Breguet to pieces, Strange grimly hauled his stick back. For a split-second, the fleeing Nieuport was aligned with his guns, A split-second—but it was enough. His hand clenched the Bowden grips, and the bullet-scarred guns thrashed fiercely upon his cowl.

Something flew through a shifting searchlight beam, as hurtling fragments of von Zenden's propeller sailed across the sky. The Prussian pitched the crippled Nieuport into a dive, slipped back toward the now lighted boulevard beneath. Strange side-slipped after him, with the defense ship's guns burning the air above the screaming Breguet.

Displaying the skill of a master, von Zenden brought the fighter down and to a stop at one side of the boulevard near the other defence planes. As Strange followed in, cut his switch, and levelled off, the spy leaped from his cockpit, lifted out a bundle, and ran toward another Nieuport which had just been started. Strange pushed on his rudder, and the two-seater swung straight for the idling plane. Von Zenden jumped back, and with a tight ground-loop Strange brought the Breguet to a halt, blocking the Nieuport.

A dozen poilus were running toward the spot. And as Strange and Andre jumped down from the bullet-torn Breguet, von Zenden whirled to the nearest soldiers.

"Arrest these traitors! Sergeant, have that plane moved out of the way at once—I am on an emergency flight for Marshal Foch!"

Four or five poilus surrounded the fugitives, ignoring Andre's frantic yells. The others hurriedly began to shove the Breguet aside, but before it was quite clear a Staff limousine came speeding onto the scene. It stopped with a squeal of tyres, and Marshal Foch stepped out, followed by Beeding, Srnythe, and two French staff officers.

"Thank Heavens! They've caught 'em!" sputtered Beeding. "See, they—”

“Look out!" shrieked Andre. "That diable is escaping!" Von Zenden, seeing the Nieuport almost clear, had ducked under its wing while attention was centered on Marshal Foch. At Andre's shout, be threw his bundle into the cockpit and crouched to spring after it. Strange jerked back, drove a terrific left hook to the jaw of the poilus before him, and dashed to the side of the Nieuport. Von Zenden lashed out with one foot, lost his balance, and clawed to catch himself. He hit the switch and the engine abruptly died. Strange brought him to the ground with a quick tackle.

"Mon Dieu!" gasped a French staff officer, as Strange hauled the spy to his feet. "It is Captain Raimond! But I just saw him—"

There was a sudden dead silence as the assembled men stared from the made-up Prussian to the real Raimond, who had appeared from a car behind that of Marshal Foch. For a moment, von Zenden seemed about to make one last desperate attempt to escape, then he smiled with bitter irony.

"There appears to be one too many Captain Raimonds present.”

“A difficulty easily disposed of," snapped Andre. "Lieutenant Bayard, your prisoner— Oberst Karl von Zenden, of the German Military Intelligence! Hold him for the murder of Major D'Orcy and for espionage.

Marshal Foch, after a start of amazement, looked gravely at Andre. "I had confidence that these charges were wrong, Major _Andre. But there are several things I do not understand."

Andre clicked his heels as smartly as he could considering that three poilus were still hanging onto him.

"If you will permit me, my General, I can show you the main reason for everything,"

The Field Marshal nodded to the poilus holding the captives, and the men stepped back, Andre went to the Nieuport, and returned with the bundle von Zenden had secreted in it. Marshal Foch paled as the red books and the key-map were revealed, and the surrounding Staff officers stared at them in consternation. The hush was broken by a thud. Strange looked around quickly.

Colonel Beeding had fainted.

Everything has been attended to monsieur le Marshal" said Lieutenant Bayard. He stood stiffly before Marshal Foch's huge desk at the War Ministry. "We found the secret door to the cloakroom. It had been blown open by the explosion of the grenades. Captain Strange guided us to the pivoted stone, and we found the spy den as he and Major Andre described. My men, using gas-masks, recovered evidence substantiating their story. Also, we have caught all but two of the spies who attempted to escape by using the Fifth Escadrilles planes. They were trapped by machine-gun platoons as they emerged from the culvert. The two who ran back into the sewer will be found soon.”

“Very good work, lieutenant," said Marshal Foch in a kindly voice. He stood up, turned and held out his hand to Andre and then to Strange. "I never doubted either of you. France is deeply in your debt, and I, too. You will be decorated, of course. And if there is any request I might grant, name it.”

“General," said Strange, with a twinkle in his eyes, "a hot bath, a glass of champagne, and a rare steak would loom larger in my estimation at this time than all the decorations France could bestow—if you will forgive me.

Marshal Foch laughed, and they went out. As they passed through the adjoining room they saw von Zenden being grilled by several intelligence officers. The Prussian, devoid of make-up, glanced at them with a baffled expression.

"Perhaps now, you will explain how you escaped from that place?" he said to Strange.

The G-2 ace shook his head. "A magician should never explain his tricks.”

“I asked," von Zenden said mockingly, "because I may have need of such magic.”

“It would do you no good," Andre said with a grim smile.

"What do you mean!" demanded the Prussian.

"You buried us alive," said Andre. "When we finally bury you, you will be very, very dead."

finis