There was a niche in the wall, which Thorn had not seen. Sylva was there, sleeping the same heavy, dreamless sleep from which Thorn himself had just awakened. He went to her swiftly. She was breathing naturally, though tears from the irritating gas still streaked her face and her skin seemed to be pinkened a little from the same cause.

Thorn swung around. His weapons were gone, of course. The huge man snapped on the induction-screen switch again and put down his weapon.

With that screen separating the room into two halves, no living thing could cross it without either such muscular paralysis as Thorn had just experienced, or death. Coils in the floor induced alternating currents in the flesh itself, very like those currents used for supposed medical effects in "medical batteries," and "shockers."

"Be calm!" said Kreynborg, chuckling. "I am pleased to haff company.

This is der loneliest spot in der Rockies. It was chosen for that reason. But I shall be here for maybe months, and now I shall not be lonely. We of der Com-Pubs haff scientific resources such as your fools haff nefer dreamed of, but there is no scientific subst.i.tute for a pretty woman."

He turned again to the writing device. It clicked half a dozen times more, and he stopped. A strip of paper came out of it. He inserted it into the slot of another mechanism and switched on a standard G.C.

phone as the paper began to feed. In seconds the room was filled with unearthly hoots and wails and whistles. They came from the device into which the paper was feeding, and they poured into the G.C.

transmitter. They went on for nearly a minute, and ceased. Kreynborg shut off the transmitter.

"My code," he observed comfortably, "gifing der good news to Stalingrad. Everything is going along beautifully. I roused der fair Sylva and kissed her a few times to make her scream into a record, and I interpolated her screamings into der last code transmission. Your wise men think der Martians haff vivisected her. They are concentrating der entire fighting force of der United Nations outside der dome of force. And all for a few kisses!"

Thorn was white with rage. His eyes burned with a terrible fury. His hands shook. Kreynborg chuckled again.

"Oh, she is unharmed--so far. I haff not much time now. Presently der two of you will while away der time. But not now."

He switched on the G.C. receiver and the room filled with a mult.i.tude of messages. Thorn sat beside Sylva, watching, watching, watching, while invisible machinery whined softly and Kreynborg listened intently to the crisp, curt official reports that came through on the Fighting Force band. Three combat-squadrons were on the spot now; One, Three and Eight. Four more were coming at fast cruising speed--four hundred miles an hour. One combat-squadron of the whole fleet alone would be left to cope with all other emergencies that might arise.... A television screen lighted up and Thorn could see where the lenses on the bulbous tower showed the air all about filled with fighting-planes, hovering about the dome of force like moths beating their wings against a screen. The strongest fighting-force in the world, helpless against a field of electric energy!

"It is amusing," chuckled Kreynborg, looking at the screen complacently. "Der dome of force is a new infention. It is a heterodyning of one frequency upon another at a predetermined distance. It has all der properties of matter except ma.s.s and a limit of strength. There is no limit to its strength! But it cannot be made except in a sphere, so at first it seemed only a defensif weapon. With it, we could defy der United Nations to attack us. But we wished to do more. So I proposed a plan, and I haff der honor of carrying it out.

If I fail, Kra.s.sin disavows me. But I shall not fail, and I shall end as Commissar for der continent of North America!"

He looked wisely at Thorn, who sat motionless.

"You keep quiet, eh, and wait for me to say something indiscreet?

Ferry well, I tell you. We are in a sort of gold-fish globe of electric force. Your air fleet cannot break in. You know that! Also, if they were in they could not break out again. So I wait, fery patiently pretending to be a Martian until all your Fighting Force has gathered around in readiness to fight me. But I shall not fight. I shall simply make a new and larger gold-fish globe, outside of this one. And then I go out and make faces at der Fighting Force of der United Nations imprisoned between der two of them--and then der Com-Pub fleet comes ofer!"

He stood up and put his hand on a door-k.n.o.b.

"Is it not pretty?" he asked blandly. "In two weeks der air fleet will begin to starfe. In three, there will be cannibalism, unless der Com-Pubs accept der surrender. Imagine...." He laughed. "But do not fear, my friendt! I haff profisions for a year. If you are amusing, I feed you. In any case I exchange food for kisses with der charming Sylva. It will be amusing to change her from a woman who screams as I kiss her, to one who weeps for joy. If I do not haff to kill you, you shall witness it!"

He vanished through a doorway on the farther side of the room.

Instantly Thorn was on his feet. The dead slumber in which Sylva was sunk was wholly familiar. Electric anesthesia, used not only for surgery, but to enforce complete rest at any chosen moment. He dragged her from that couch to his own. He saw her stir, and her eyes were instantly wide with terror. But Thorn was tearing the couch to pieces.

Cover, pneumatic mattress.... He ripped out a loosely-fitting frame-piece of steel.

"Quick, now," he said in a low tone, "I'm going to short the induction-screen. We'll get across it. Then--out the door!"

She struggled to her feet, terrified, but instantly game. Thorn slid the rod of metal across the stretch of flooring he had previously been unable to cross. The induced currents in the rod amounted to a short-circuit of the field. The rod grew hot and its paint blistered smokily. Thorn leaped across with Sylva in his wake. He pointed to the door, and she fled through it. He seized a chair, crashed it frenziedly into the television screen, and had switched on the G.C.

phone when there was a roar of fury from Kreynborg. Instantly there was the spitting sound of a pocket-gun and in the red room the racking crash of a hexynitrate pellet. Nothing can stand the instant crash of hexynitrate. Its concussion-wave is a single pulsation of the air. The cellate diaphragm of the G.C. transmitter tore across from its violence and Thorn cursed bitterly. There was no way, now, of signaling....

A second racking crash as a second pellet flashed its tiny green flame. Kreynborg was using a pocket-gun, one of those small terrible weapons which shoot a projectile barely larger than the graphite of a lead pencil, but loaded with a fraction of a milligram of hexynitrate.

Two hundred charges would feed automatically into the bore as the trigger was pressed.

Thorn gazed desperately about for weapons. There was nothing in sight.

To gain the outside world he had to pa.s.s before the doorway through which the bullets had come.... And suddenly Thorn seized the code-writer and the device which transmitted that code as a series of unearthly noises which the world was taking for Martian speech. He swung the two machines before the door in a temporary barrier.

Whatever else Kreynborg might be willing to destroy, he would not shoot into them!

Thorn leaped madly past the door as Kreynborg roared with rage again.

He paused only to hurl a chair at the two essential machines, and as they dented and toppled, he fled through the door and away.

Sylva peered anxiously at him from behind a huge boulder. He raced toward her, expecting every second to hear the spitting of Kreynborg's pocket-gun. With the continuous-fire stud down, the little gun would shoot itself empty in forty-five seconds, during which time Kreynborg could play it upon him like a hose that spouted death. But Thorn had done the hundred yards in eleven seconds, years before. He bettered his record now. The first of the little green flashes came when he was no more than ten yards from the boulder which sheltered Sylva. The tiny pellet had missed him by inches. Three more, and he was safe from pursuit.

"But we've got to get away!" he panted. "He can shoot gas here and get us again! He can cover four hundred yards with gas, and more than that with guns."

They fled down a tiny water-course, midget figures in an infinity of earth and sky, scurrying frenziedly from a red slug-like thing that lay askew in a mountain valley. Far away and high above hung the war-planes of the United Nations. Big ones and little ones, hovering in hundreds about the outside of the dome of force they could neither penetrate nor understand.

A quarter of a mile. Half a mile. There was no sign from Kreynborg or the rocket-ship. Thorn panted.

"He can't reach us with gas, now, and it looks like he doesn't dare use a gun. They'd know he wasn't a Martian. At night he'll use that helicopter, though. If we can only make those ships see us...."

They toiled on. The sun was already slanting down toward the western sky. At four--by the sun--Thorn could point to a huge air-dreadnaught hanging by lazily revolving gyros barely two miles away. He waved wildly, frantically, but the big ship drifted on, unseeing. The Fighting Force was no longer looking for Thorn and Sylva. They had been carried into the rocket-ship fourteen hours and more before.

Sylva's screaming had been broadcast with the weird hoots and whistles the United Nations believed to be the language of inter-planetary invaders. The United Nations believed them dead. Now a watch was being kept on the rocket-ship, to be sure, but it was becoming a matter-of-fact sort of vigilance, pending the arrival of the rest of the Fighting Force and the cracking of the dome of force by the scientists who worked on it night and day.

On level ground, Thorn and Sylva would have reached the edge of the dome in an hour. Here they had to climb up steep hillsides and down precipitous slopes. Four times they halted to make frantic efforts to attract the attention of some nearby ship.

It was six when they came upon the rim. There was no indication of its existence save that three hundred yards from them boughs waved and leaves quivered in a breeze. Inside the dome the air was utterly still.

"There it is!" panted Thorn.

Wearied and worn out as they were, they hurried forward, and abruptly there was something which impeded their movements. They could reach their hands into the impalpable barrier. For one foot, two, or even three. But an intolerable pressure thrust them back. Thorn seized a sapling and ran at the barrier as if with a spear. It went five feet into the invisible resistance and stopped, shot back out as if flung back by a jet of compressed air.

"He told the truth," groaned Thorn. "We can't get out!"

Long shadows were already reaching out from the mountains. Darkness began to creep upward among the valleys. Far, far away a compact dark cloud appeared, a combat-squadron. It swept toward the dome and dissociated into a myriad specks which were aircraft. The fliers already swirling about the invisible dome drew aside to leave a quadrant clear, and Combat-Squadron Seven merged with the rest, making the pattern of dancing specks markedly denser.

"With a fire," said Thorn desperately, "they'll come! Of course! But Kreynborg took my lighter!"

Sylva said hopefully:

"Don't you know some way? Rubbing sticks together?"

"I don't," admitted Thorn grimly, "but I've got to try to invent one.

While I'm at it, you watch for fliers."

He searched for dry wood. He rubbed sticks together. They grew warm, but not enough to smoke, much less to catch. He muttered, "A drill, that's the idea. All the friction in one spot." He tugged at the ring under his lapel and the parachute fastened into his uniform collar shot out in a billowing ma.s.s of gossamer silk, flung out by the powerful elastics designed to make its opening certain. Savagely, he tore at the shrouds and had a stout cord. He made a drill and revolved it as fast as he could with the cord....