Lance rose. His face was alight, his eyes burning with strong, unquenchable fire.

"It's great, sir, great! It can't fail! By G.o.d, if it takes every last drop of my blood, I'll help Hay put this through!"

Colonel Douglas extended his right hand and Lance's met it in a firm shake. In the thick silence they stood thus for some minutes. Then, without moving so much as a cheek muscle, the colonel whispered, his eyes tense:

"_The door! Fling it open! I think someone's been listening!_"

Lance switched his alarmed gaze to it. His muscles went taut. The next moment he had leaped half across the room, jammed back the lock, and ripped the door wide.

At the other end of the dim pa.s.sageway he glimpsed a scurrying figure!

Lance sprang after it with a shout to Douglas. Tearing out his automatic, he flung a burst of lead at the figure, but that instant it wheeled and sped from sight down another pa.s.sage. And when Lance got there, no one was in sight.

For awhile he probed around, desperately, but could find no sign of anything. The base slept. Sorely troubled, he returned to find the colonel just coming back from an equally barren search:

"Don't think he heard much," said Douglas grimly. "It must have been that d.a.m.ned spy who's been getting information of our movements. I'll have the guards redoubled to prevent him from getting anything through." He smiled at sight of Lance's anxious face. "No need for too much worry, Lance! He couldn't have heard much--the walls are sound-proof and the door fairly tight. Now, you go and rip off some sleep! You need it! No more work for you till Wednesday night--you're too important!"

Sleep! Lance only wished he could. But the thrill of what he'd just heard was too fresh, too new; the blood pumped surgingly through his veins; his brain whirled with the thought of the glorious enterprise he and Hay were aiding so vitally.

Then, too, the night was humid and sweaty. For a while Lance lay on his cot, other sleeping figures to left and right of him, but his own eyes simply would not stay closed. Finally, after perhaps an hour of trying to doze off, he arose and, clad only in breeches and undershirt, wandered outside again with a cigarette glowing in his mouth.

The war might not have been, the night was so silent. Lance strolled lazily around the plane hangars, revelling in what little breeze there was. He seemed to be the only living thing abroad in the night.

Then, suddenly, he flung down his cigarette and ground the b.u.t.t out quickly. For he saw he was not the only living thing abroad in the night. Sliding rapidly away from the end hangar was a dark form!

Lance crouched instinctively and crept forward. Who was the other wanderer? Not a sentry: they paced a regular beat closer to Douglas'

office. Not another, who, like himself, could not sleep and had sought the open. This figure was going somewhere! It had a definite object in mind!

Sheltering himself behind the hangars' bulk, Lance advanced as stealthily as he could. Coming to the end one, he peered round its blunt corner. Fifty yards ahead, crossing a stubbly stretch of open ground, the mysterious prowler hurried onward.

The night was dark, the moon troubled by ragged bursts of listless, heavy clouds. Lance bent almost double and left the shelter of the black hangar. Feeling his way carefully, he followed the other.

Was this the unknown spy? The spy, going to transmit the news he had overheard?

Lance muttered a curse. He had no weapon with him; the spy, if he were a spy, would certainly be armed. But that didn't matter; it was merely unfortunate. He must track the other down, at all cost.

For some minutes he crept on in this manner. The other kept hurrying forward. Lance noted a clump of brush far ahead; the figure was evidently making for this. And sure enough, as if acting directly on Lance's thought, the dark form entered the patch of growth--and did not come out on the other side.

Lance broke into a trot, eyes wary and alert for sign of his prey. At any second he might be greeted by a salvo of bullets, and every fiber of his lean body was taut.

As he approached the clump of brush he dropped to the ground, and came finally to it on his belly. From a distance of about ten feet, he rose and charged.

Expecting each moment to hear the spit of a revolver, he was more alarmed by what actually did greet him.

Nothing. The patch of brush was empty!

"Well I'll be d.a.m.ned!" Lance murmured. "Where did he get to?"

He gazed around, bewildered. The growth of bush was about ten feet wide. On either side the flat Nevada plain stretched away--empty. No figure was visible.

Lance was utterly baffled. The fellow had vanished as if by magic.

Flown away into thin air!

The young captain stood quite still, listening, probing his puzzled brain.

Then, like a cat, he dropped to the ground again, and pressed an ear to it. For his ears had caught a tiny betraying hum.

A hum! There was a machine of some type near him. He listened intently. The hum came from the ground on which he lay. There had to be a trap-door.

Lance's fingers scrabbled around, and presently found what they looked for.

He seized the ring which enabled one to pull the trap-door back, and was just about to pull when he heard, from below, a voice speaking in Russian. It was, then, the spy!

Lance grasped the ring anew, and, exerting all his strength, hauled the trap-door back.

A narrow pa.s.sageway was revealed, lit by a lamp. The hum burst with doubled force on his ears. He plunged down, fists clenched, and half tumbled into a tiny room gouged from the soil.

At one end was a ma.s.s of machinery, and a microphone hung suspended before it. And speaking into the microphone was the heavy-set form of a man in American uniform, his back to Lance. As the latter charged down, he rose with an alarmed shout, and wheeled around.

"My G.o.d!" breathed Lance.

It was Ranth, Colonel Douglas' orderly!

Ranth!

His dark face flushed with fury, he came leaping from his seat. The wicked little revolver hung at his belt sprang out, but Lance's right fist shot forward, knocked Ranth's hand high and sent the gun clattering to the ground. Then, for a moment, they faced each other, the hum of the radiophone droning an ominous accompaniment.

"You!" Lance muttered. "So you were the spy!"

Ranth answered him with a choked oath and leaped forward again.

There were no niceties to that combat. It was a matter of life and death, and each knew it. Ranth would kill him, Lance knew, if he possibly could; and he, he had to kill or capture Ranth. Otherwise the news of the Torpedo Plan would go through, Ranth would return to the base, and the secret of the hidden radio never be known. Another would be put in Lance's place; and when Hay kept his rendezvous at Sola Ranch....

He had to win.

No effort was made at defense, for those first few furious minutes. A veritable fusillade of hurtling fists stormed through the air. They each gave and took equally. Then Ranth's heavy shoulders bunched; cunningly he feinted, then, whirling, swung a vicious right hand smash to Lance's chin.

Lance reeled, fell, seeing Ranth's hate-contorted visage dance queerly in the close air before him. The orderly clutched for his revolver, and Lance bounded up as if spring-impelled, nailed the other with two lightninglike jabs and unleashed all his strength in an uppercut which sprawled Ranth in a limp, quivering heap.