All stuffed their ears with cotton wool, and crowded against one end of the chamber. Anthony had the end of a long double wire in his hand, and it curled across the floor to the farther wall. He pressed the b.u.t.ton of a pear-switch--and there was a concussion that hurled the watchers against the wall behind them. A great gap appeared in the farther wall, beyond it a black chasm, and a helicopter that was dimly illumined by the light from within the room. A quick inspection of the flier revealed that its alumino-steeloid had been unaffected by the pa.s.sage of time, and Allan climbed into it. A wave of his hand simulated an insouciance he did not feel. Then he was rising through darkness. The sun's light struck down and enveloped him, and he was in the open air. He rose above the trees.

Desolation spread out beneath him. In all the vastness that unfolded as the lone 'copter climbed into a clear sky, nothing moved. The air, that from babyhood Allan had seen crowded with bustling traffic, was a ghastly emptiness. Not even a tiny, wheeling speck betrayed the presence of a bird. And below--the gas that was fatal to animal life seemed to have stimulated vegetable growth--an illimitable sea of green rolled untenanted to where the first ramparts of New York rose against the sky. Roads, monorail lines, all the countless tracks of civilization had disappeared beneath the green tide. Nature had taken back its own.

Heartsick, he turned south, and followed the silver stream of the Hudson. The river, lonely as the sky, seemed to drift oily and sluggish down to plunge beneath the city at the lower end of the Tappan Zee. Allan Dane came over New York, gazed down at the ruin of its soaring towers, at the leaping arabesque of its street bridges. He peered into vast rifts of tumbled, chaotic concrete and steel. Nothing moved in all that spreading wonder that had housed twenty millions of people.

Allan drifted lower, and saw that from what had been gardened roof-parks, now a welter of strewn earth, the green things had spread till they covered the heaped jetsam with a healing blanket of foliage.

Not all the city had been laid waste, however. Here and there, great expanses of the cliff-like structures still stood, undamaged, and in the midst of one of these areas he saw the high-piled edifice to which he had been directed. Its roof was lush with vegetation but by dextrous handling he set his helicopter down upon it.

The engine roar diminished and died. Silence folded around him, a black, thick blanket.

Dane got heavily from his seat, oppressed by the vast soundlessness, and pushed through curling plants that caught at his heels. The sound of his pa.s.sage was like crackling thunder. A decaying door was marked, in faded, almost undecipherable letters, "Emergency Stairs." It was half open, and Allan squeezed around its edge. Spiral steps curved down into blackness. He hesitated a moment. He could _feel_ the awful silence, the emptiness below was a pit of death. Anthony's words came back to him, echoed in his ears: "We seven are the only living humans left on Earth."

In that moment, out of the pitch-black well of soundlessness, a scream shrilled! No words, only a red, thin thread of sound, rising, and falling, and rising again out of depths where not even a living mouse should be! It came again, ripping the silence--a woman's scream, high-pitched, quivering with fear!

Allan plunged down into the darkness, caroming from wall to wall as he half ran, half fell, down the twisting stairs. Another sound reverberated from unseen walls, and Dane realized that it was his own voice, shouting.

His feet struck level floor. A pale rectangle of light showed before him, and he dived through it. He was in a corridor, dim-lit by phosph.o.r.escent fungi that cloaked the damp walls. He halted, at fault. The long hall stretched away to either side, cluttered with grimed bones, slimy with mold. By the age-blistered name cards on closed doors he knew himself to be on a residential level. But which way should he turn? Whence had come that scream? He crouched against the wall, his heartbeats thudding loud in his ears, and listened for a clue.

A m.u.f.fled sound of scuffling came from his left. Allan whirled toward it and sped down the corridor. He was breathing in great gasps, and the air he breathed was thick and musty. Too late to stop, he saw a slick of green slime on the floor. His foot struck it, flew out from under him, he fell and slid headlong.

Something stopped him, something that crunched sickeningly as his sliding body crashed into it: two skeleton forms, clasped in each others' arms, moldering fabric hanging in rags from them. They lay across the threshold of a door, and just within Dane heard snarls, snufflings, b.e.s.t.i.a.l growls, the sounds of a struggle. Something thumped against the door and fell away. He heaved to his feet and his hand found the doork.n.o.b. But suddenly he was powerless to turn it.

Panic tugged at him with almost palpable fingers, drove him to go back to his plane and safety. Almost he fled--but he remembered in time that it was a _human_ scream he had heard.

The portal gave easily to his lunge. Bluish light flooded the chamber, dazzling after the fungous dimness. A bulking form, whether ape or man he could not make out, so brutish the face, so hairy the dark body revealed by its tattered rags bent over the sprawled shape of a girl.

Dane saw her in a fleeting glimpse--the slim length of her, the tumbled, golden hair half hiding, half revealing white curves of beauty, a shoulder from which the tunic had been torn away. Then her attacker whirled toward the intruder. Allan leaped from the threshold, his fist arcing before him. The blow landed flush on the other's jaw.

Yellow, rotted fangs showed in a jet-black face, and the huge Negro lunged for Dane, roaring his rage. Before the American could dodge or strike again the other's long arms were around him. Allan was jerked against a barrel chest, felt his bones cracking in a terrific hug.

Eyes, tiny and red, stared into his. Dane drove knees and fists into the Negro, but the awful pressure of those simian arms across his back increased till he could no longer breathe. The American was almost gone, the black face blurred, and the continuous snarling of the brute was dull in his ears.

Suddenly Dane went limp. Victory flashed into the red eyes. The squeezing arms relaxed, and in that moment Allan's legs curled around the black's, heels jerking into the hollows behind his captor's knees.

At the same instant, levering from that heel hold, Dane b.u.t.ted sharply up against the rocky jaw. All the strength that was left in him went into that trick, and it worked! The Negro crashed backward to the floor. Allan twisted, and rolled free. He was up, looking desperately around for some weapon. But it was not needed; the hulk on the floor never moved. The back of the Negro's head had smashed against the floor, and he was out.

Dane turned and bent to the girl. She, too, was motionless, but to his relief her breast rose and fell steadily. He glanced about looking for water to revive her. Then he saw that this room was sheathed with nullite. Then this was one of the chambers prepared before the plans were changed. But the girl could not be of the fourth couple--the missing two that had never appeared. She was no more than eighteen.

And whence had come the giant black who had attacked her?

"Stick up your hands. Quick!"

Allan whirled to the sudden challenge. The man in the doorway was pointing a ray-gun steadily at him! Dane's hands went up, and he gasped inanely: "Who are you?"

"What is going on here? Where did you come from?" The newcomer's English was precise, too precise. No hulking brute, this. A yellow man, slitted eyes slanted and malevolent; broad, flat nose above thin lips that were purple against the saffron skin. The uniform he wore showed signs of some attempt to keep it in repair, and to its threadbare collar still clung a tarnished insignia: the seven-pointed star, emblem of the enemy Allan had fought on a yesterday that was two decades gone.

"Well? Have you lost the power of speech?" The ray-gun jerked forward impatiently.

An obscure impulse prompted Allan's reply. "Almost. I've spoken to no one for twenty years."

"So-o,"--softly. The Oriental's eyes flicked past Dane, and a sudden light glowed in them. "You have been alone for twenty years in this city we thought was empty, but you were on hand to fight with Ra-Jamba for this delightful creature." Something leered from his face that sent the hot blood surging to Allan's temples. The Easterner stepped catlike into the room, shutting the door behind him with his free hand.

"That is true," the American said, with what calmness he could muster. Through the dizzy whirl of his mind he clung to one thought: he must conceal the existence of the little group on Sugar Loaf Mountain at all costs. "I had just discovered that it was safe to leave the room, similar to this, in which I had hidden from the gas, when I heard a scream. I reached here just in time to--"

"To interfere with Ra-Jamba's pleasure, and save the little white dove--for me. My thanks." The yellow man bowed mockingly. "Too bad,"

he purred, "that you should be robbed of the spoils of your fight."

Then he asked irrelevantly. "So some of you Americans found a way to cheat our gas. How many?"

Allan temporized. There had been several similar refuges prepared, he said, but he did not know whether they had been used. This was the first he had visited beside his own. But how was it that the questioner knew so little about what had happened here? Had his people simply laid this country waste and never revisited it?

The Oriental shrugged. "My people are gone, wiped out by your gas as yours were wiped out by ours." He retold Anthony's story. "The crew of my own ship mutinied," he concluded. "We fled north, from that last terrible fight, north, ever north, till at the top of the world we found a little s.p.a.ce that was not gas-covered. There was nothing there, just the ice, and the snow, and the cold. We lived there, twelve of us, all men. There were a few bears and seals. We slew them for food--and we grew a little mad. We were men--all men--do you understand?"

As he said this last, his thin voice rose to a shriek, and his eyes darted to the girl's rec.u.mbent form. At length, he went on, the gas began to retreat, and they followed it down. They had searched town after town, city after city, had found food in plenty, and all the trappings of civilization. But there was never a living being. And the fever in their blood drove them on.

That very morning the insane search had reached New York. They had landed on the roof of this very building. "We separated to hunt--and Ra-Jamba was the lucky one. But I--Jung Sin--am still luckier." He crept nearer to Allan, and tapped him on the chest with his weapon.

"For look you--while those fools used all their ray-gun charges, even the charge of the big tube on our ship, to kill food, I husbanded mine." He laughed shrilly. "So you see, I have the only ray-gun in the world. It shall make me master of the Earth." Again he laughed wildly.

"Now I'm going to kill you." The black cylinder leveled, and Dane stared at death. Alone, he would almost have welcomed it, but the thought of the girl in the filthy power of this beast seared through him. Jung Sin, the little red worms of madness crawling in his brain, paused for a final taunt.

"Let the thought of the white dove in my arms cons--" Allan's sandaled foot shot out into the man's stomach. In the same movement his hands came down, one s.n.a.t.c.hed at and caught the ray-gun, the other smashed into the yellow face. Jung Sin lifted to the drive of fist and foot, crashed into the wall, fell to its foot. From the crumpled heap rose a shriek, a long piercing wail that ended in a gurgle.

Dane froze, the captured cylinder in his hand, and listened. There were others of the unholy band about. Had they heard? Dim sounds came to him. He leaped to the door, flung it open. Faint footfalls, a distant shout, came from far down the corridor, away from the direction of the stairs. Allan glimpsed dark forms, rushing toward him. He darted back to the girl, swung her, still unconscious, to his shoulder, and was out. The floor was slippery beneath his feet. He reeled as he ran, and the sounds of pursuit gained on him. The heavy burden weighed him down, the dim hallway stretched endlessly before him. From close behind came hoa.r.s.e, guttural shouts that chilled him.

The pack was not twenty feet away when Allan reached the stair door.

He slammed it behind him, heard the latch click. He mounted the narrow, winding steps with the last dregs of energy draining from him, and heard a crash below that told of the collapse of the barrier. But he had reached his plane, had flung the girl into it, and was pulling himself in when the first of the pursuers burst out on the roof.

Allan thrust home the throttle, the helio-vanes whined, and his 'copter leaped skyward. He glimpsed men running across the roof; they vanished behind a leafy arbor. Dane turned the nose of his craft toward Sugar Loaf, amethyst in the haze of distance, but from that green arch a black aircraft zoomed up and shot after him. The American shook his head free of the cobwebs of fatigue, and veered westward. He must not lead the Easterners to Anthony's refuge.

Through the dead air, over a dead world they shot--Allan's white flier and the ebony plane with the b.l.o.o.d.y emblem of the seven-pointed star emblazoned on its nose. Allan wheeled again as the pursuers reached his level on a long, climbing slant.

But they continued rising! They, were five hundred, a thousand feet above him. Then they leveled out, and dived down. Their strategy flashed on him--they were planning to shepherd Dane down, to force him to land where they would have him at their mercy. And their craft was the faster!

The black ship was right on his tail; Allan flicked his controls and his 'copter slid sidewise on one wing. The other plane banked in a tight arc and sped for him; Dane countered with a lightning loop that brought him behind his enemy. His gray eyes were steel-hard, his lips were a straight, thin gash. The other ship was faster, but his, lighter and smaller, was more flexible. He could not get away, but--They flipped up and back in an inside loop; Allan's little craft barrel-rolled from under.

This sort of thing could not last forever. With each maneuver he was losing alt.i.tude. Serrated roof-tops were already a scant fifteen hundred feet beneath him, gaunt gray fingers that reached up to pluck him from the sky.

Only half Allan's mind was concentrated on the aerial acrobatics. The other half plodded a weary treadmill. In the nullite chamber beneath Sugar Loaf's summit, he thought, were three couples whose knowledge and wisdom had preserved them for the repeopling of the Earth. Their children, and their children's children--starting from such a source what heights might not the new race attain?

On the other hand, the ship that pursued him carried cowards who had failed in mankind's supreme test; men who had lost their manhood, ravening demi-beasts, half mad with loneliness and desire. As long as they remained alive they would be a menace to those others, an unclean band that would forever sully the new world with the old world's evils. Even should Allan himself escape them by some trick of fortune, they must inevitably find the little band of men--and women. A cold chill ran through Dane as he visioned the result.

He was not afraid to die. And the girl in the cabin behind him--better that she never awake than that she be the sport of Ra-Jamba's kind. A grim resolve formed itself, and he watched for a chance to put it into execution.