The creature vanished before he could draw his weapon, but in the shadows lurked other figures, other eyes that seemed alight with nonhuman intelligence. He fired, and a curious squawling cry came back, and it seemed to him that the forms receded for a time. But they came again, and he saw without surprise the nightmare horde of creatures.
He stuffed the notebook in his pocket and seized Lilith's wrist, for she stood as if paralyzed by horror. He backed away out of the doorless entrance, over the narrow brook. The girl seemed dazed, half hypnotized by the glimpses of the things that followed them. Her eyes were wide with fear, and she stumbled after him unseeing. He sent another shot into the shadows.
That seemed to rouse Lilith. "Lay shot!" she whimpered, then gathered her self-control. She uttered her curious call, and somewhere it was answered, and yet further off, answered again.
Her pack was gathering for her defense, and Carver felt a surge of apprehension for his own position. Might he not be caught between two enemies?
He never forgot that retreat down the course of the little stream. Only delirium itself could duplicate the wild battles he witnessed, the unearthly screaming, the death grips of creatures not quite natural, things that fought with the mad frenzy of freaks and outcasts. He and Lilith must have been slain immediately save for the intervention of her pack; they slunk out of the shadows with low, bestial noises, circling Carver cautiously, but betraying no scrap of caution against — the other things.
He saw or sensed something that had almost escaped him before. Despite their forms, whatever their appearance happened to be, Lilith's pack was doglike. Not in looks, certainly; it was far deeper than that. In nature, in character; that was it.
And their enemies, wild creatures of nightmare though they were, had something feline about them. Not in appearance, no more than the others, but in character and actions. Their method of fighting, for instance — all but silent, with deadly claw and needle teeth, none of the fencing of canine nature, but with the leap and talons of feline. But their aspect, their — their catness was more submerged by their outward appearance, for they ranged from the semi-human form of the little demon of the brook to ophidian-headed things as heavy and lithe as a panther. And they fought with a ferocity and intelligence that was itself abnormal.
Carver's gun helped. He fired when he had any visible target, which was none too often; but his occasional hits seemed to instill respect into his adversaries.
Lilith, weaponless save for stones and her wooden knife, simply huddled at his side as they backed slowly toward the beach. Their progress was maddeningly slow, and Carver began to note apprehensively that the shadows were stretching toward the east, as if to welcome the night that was sliding around from that half of the world. Night meant — destruction.
If they could attain the beach, and if Lilith's pack could hold the others at bay until Carver could build a fire, they might survive. But the creatures that were allied with Lilith were being overcome. They were hopelessly outnumbered. They were being slain more rapidly with each one that fell, as ice melts more swiftly as its size decreases.
Carver stumbled backward into orange-tinted sunlight. The beach! The sun was already touching the coral spit, and darkness was a matter of minutes — brief minutes.
Out of the brush came the remnants of Lilith's pack, a half dozen nondescripts, snarling, bloody, panting, and exhausted. For the moment they were free of their attackers, since the catlike fiends chose to lurk among the shadows. Carver backed farther away, feeling a sense of doom as his own shadow lengthened in the brief instant of twilight that divided day from night in these latitudes. And then swift darkness came just as he dragged Lilith to the ridge of the coral spit.
He saw the charge impending. Weird shadows detached themselves from the deeper shadows of the trees. Below, one of the nondescripts whined softly. Across the sand, clear for an instant against the white ground coral of the beach, the figure of the small devil with the half-human posture showed, and a malevolent sputtering snarl sounded. It was exactly as if the creature had leaped forward like a leader to exhort his troops to charge.
Carver chose that figure as his target. His gun flashed; the snarl became a squawl of agony, and the charge came.
Lilith's pack crouched; but Carver knew that this was the end. He fired. The flickering shadows came on. The magazine emptied; there was no time now to reload, so he reversed the weapon, clubbed it. He felt Lilith grow tense beside him.
And then the charge halted. In unison, as if at command, the shadows were motionless, silent save for the low snarling of the dying creature on the sand. When they moved again, it was away — toward the trees!
Carver gulped. A faint shimmering light on the wall of the forest caught his eye, and he spun. It was true! Down the beach, down there where he had left his box of supplies, a fire burned, and rigid against the light, facing toward them in the darkness, were human figures. The unknown peril of fire had frightened off the attack. He stared. There in the sea, dark against the faint glow of the West, was a familiar outline. The Fortune! The men there were his associates; they had heard his shots and lighted the fire as a guide.
"Lilith!" he choked. "Look there. Come on!"
But the girl held back. The remnant of her pack slunk behind the shelter of the ridge of coral, away from the dread fire. It was no longer the fire that frightened Lilith, but the black figures around it, and Alan Carver found himself suddenly face to face with the hardest decision of his life.
He could leave her here. He knew she would not follow, knew it from the tragic light in her honey-hued eyes. And beyond all doubt that was the best thing to do; for he could not marry her. Nobody could ever marry her, and she was too lovely to take among men who might love her — as Carver did. But he shuddered a little as a picture flashed in his mind. Children! What sort of children would Lilith bear? No man could dare chance the possibility that Lilith, too, was touched by the curse of Austin Island.
He turned sadly away — a step, two steps, toward the fire. Then he turned.
"Come, Lilith," he said gently, and added mournfully, "other people have married, lived, and died without children. I suppose we can, too."
The Fortune slid over the green swells, northward toward New Zealand. Carver grinned as he sprawled in a deck chair. Halburton was still gazing reluctantly at the line of blue that was Austin Island.
"Buck up, Vance," Carver chuckled. "You couldn't classify that flora in a hundred years, and if you could, what'd be the good of it? There's just one of each, anyway."
"I'd give two toes and a finger to try," said Halburton. "You had the better part of three days there, and might have had more if you hadn't winged Malloa. They'd have gone home to the Chathams sure, if your shot hadn't got his arm. That's the only reason they made for Macquarie."
"And lucky for me they did. Your fire scared off the cats."
"The cats, eh? Would you mind going over the thing again, Alan? It's so crazy that I haven't got it all yet."
"Sure. Just pay attention to teacher and you'll catch on." He grinned. "Frankly, at first I hadn't a glimmering of an idea myself. The whole island seemed insane. No two living things alike! Just one of each genus, and all unknown genera at that. I didn't get a single clue until after I met Lilith. Then I noticed that she differentiated by smell. She told good fruits from poisonous ones by the smell, and she even identified that first cat-thing I shot by smell. She'd eat that because it was an enemy, but she wouldn't touch the dog-things I shot from her pack."
"So what?" asked Halburton, frowning.
"Well, smell is a chemical sense. It's much more fundamental than outward form, because the chemical functioning of an organism depends on its glands. I began to suspect right then that the fundamental nature of all living things on Austin Island was just the same as anywhere else. It wasn't the nature that was changed, but just the form. See?"
"Not a bit."
"You will. You know what chromosomes are, of course. They're the carriers of heredity, or rather, according to Weissman, they carry the genes that carry the determinants that carry heredity. A human being has forty-eight chromosomes, of which he gets twenty-four from each parent."
"So," said Halburton, "has a tomato."
"Yes, but a tomato's forty-eight chromosomes carry a different heredity, else one could cross a human being with a tomato. But to return to the subject, all variations in individuals come about from the manner in which chance shuffles these forty-eight chromosomes with their load of determinants. That puts a pretty definite limit on the possible variations.
"For instance, eye color has been located on one of the genes on the third pair of chromosomes. Assuming that this gene contains twice as many brown-eye determinants as blue-eye ones, the chances are two to one that the child of whatever man or woman owns that particular chromosome will be brown-eyed — if his mate has no marked bias either way. See?"
"I know all that. Get along to Ambrose Callan and his notebook."
"Coming to it. Now remember that these determinants carry all heredity, and that includes shape, size, intelligence, character, coloring — everything. People — or plants and animals — can vary in the vast number of ways in which it is possible to combine forty-eight chromosomes with their cargo of genes and determinants. But that number is not infinite. There are limits, limits to size, to coloring, to intelligence. Nobody ever saw a human race with sky-blue hair, for instance."
"Nobody'd ever want to!" grunted Halburton.
"And," proceeded Carver, "that is because there are no blue-hair determinants in human chromosomes. But — and here comes Callan's idea — suppose we could increase the number of chromosomes in a given ovum. What then? In humans or tomatoes, if, instead of forty-eight, there were four hundred eighty, the possible range of variation would be ten times as great as it is now.
"In size, for instance, instead of the present possible variation of about two and a half feet, they might vary twenty-five feet! And in shape — a man might resemble almost anything! That is, almost anything within the range of the mammalian orders. And in intelligence — " He paused thoughtfully.
"But how," cut in Halburton, "did Callan propose to accomplish the feat of inserting extra chromosomes? Chromosomes themselves are microscopic; genes are barely visible under the highest magnification, and nobody ever saw a determinant."
"I don't know how," said Carver gravely. "Part of his notes crumbled to dust, and the description of his method must have gone with those pages. Morgan uses hard radiations, but his object and his results are both different. He doesn't change the number of chromosomes."
He hesitated. "I think Callan used a combination of radiation and injection," he resumed. "I don't know. All I know is that he stayed on Austin four or five years, and that he came with only his wife. That part of his notes is clear enough. He began treating the vegetation near his shack, and some cats and dogs he had brought. Then he discovered that the thing was spreading like a disease."
"Spreading?" echoed Halburton.
"Of course. Every tree he treated strewed multi-chromosomed pollen to the wind, and as for the cats — Anyway, the aberrant pollen fertilized normal seeds, and the result was another freak, a seed with the normal number of chromosomes from one parent and ten times as many from the other. The variations were endless. You know how swiftly kauri and tree ferns grow, and these had a possible speed of growth ten times as great.
"The freaks overran the island, smothering out the normal growths. And Callan's radiations, and perhaps his injections, too, affected Austin Island's indigenous life — the rats, the bats. They began to produce mutants. He came in 1918, and by the time he realized his own tragedy, Austin was an island of freaks where no child resembled its parents save by the merest chance."
"His own tragedy? What do you mean?"
"Well, Callan was a biologist, not an expert in radiation. I don't know exactly what happened. Exposure to X-rays for long periods produces burns, ulcers, malignancies. Maybe Callan didn't take proper precautions to shield his device, or maybe he was using a radiation of peculiarly irritating quality. Anyway, his wife sickened first — an ulcer that turned cancerous.
"He had a radio — a wireless, rather, in 1921 — and he summoned his sloop from the Chathams. It sank off that coral spit, and Callan, growing desperate, succeeded somehow in breaking his wireless. He was no electrician, you see.