Lane blinked. The professor gestured impatiently. He blew a smoke ring. It went slowly across the stifling hot interior of the trailer, expanding as it went.
“That,” said the professor, “is a very simple dynamic system. It’s a quantity of air which happens to have a toroidal motion. It isn’t alive. It’s only a vortex ring. You can see it because the air of which it’s composed happens to contain smoke. But a vortex ring can exist in plain air just as—”
“Aunt Ann! Look at the smoke ring!” It was Carol, her voice strained.
The professor blinked. Then she looked at the thin, drifting ring of smoke. It was deformed. It was bent on one side exactly as if it had struck something solid.
The professor said, “That’s it! There’s one now! You can see the ceiling waver through it.”
There was a sudden motion of the air. The unseeable something which had deflected the smoke ring moved. The tendrils of smoke wavered and curled through the space from which they had previously been barred.
“It’s one of them!” exulted the professor. “Right in here! But why doesn’t the Monster react? Fetch him out.”
Lane dragged the dog, cowering, from underneath a stool. He held the dog up. The brute panted and wriggled. He gave no sign of fright. His tongue lolled.
“If there is something here,” said Lane, “he doesn’t smell it. And it can’t be seen or he’d see it. It—”
There were now flat layers of tobacco smoke in the air, made visible by sunlight striking into the room through closed glass windows. There was no air movement except the extremely slow general turnover of air in a closed room, but something passed swiftly through those tranquil layers of vapor, disturbing them. It was startling. It was appalling. Lane did not see any wavering of the background behind it.
“Item!” said the professor with satisfaction. “We have a good observation indicating that there are sometimes dynamic systems in air which can move through smoke layers and disturb them. Perhaps we should provide ourselves with sheets to pull over our heads.”
She beamed at Lane, who looked warily at Carol.
“It got in, probably when the dog did,” he said grimly.
The professor rubbed her hands. “Of course!” she said zestfully. “But we know how to keep it from harming any of us! I’m going to catch this specimen and find out a few things about it!”
Lane’s eyes went back to Carol. She was watching all the interior of the trailer with steady, intent eyes—beautiful eyes, Lane thought, but troubled now.
“If it’s what we think, it’s dangerous,” Lane pointed out. “The first thing should be to get her away from this place. I feel responsible. I let the thing in here.”
“Pooh!” said the professor.
She went to a cupboard built into the wall of the trailer, and took out some folded sheets. She shook one open, lengthwise, and tossed it to her niece. It spread out in the air.
The Monster snarled. He cried out at the sheet, barking and snarling and yelping all at once, his voice rising in pitch. The professor’s mouth dropped open. The sheet fell almost upon Carol, but it didn’t reach the floor everywhere. One edge was caught up upon a stool. Besides, there was a spot where something writhed and squirmed and whined shrilly beneath it. That something was roughly rounded and somewhat more than a foot in diameter. It was caught under the cloth, and apparently could not lift it.
The Monster went mad with terror. He made a tumult of fear and ferocity together. He screamed at the somehow horrible shapelessness beneath the white cloth. Yet he cringed away from it as he made his high-pitched din.
But one edge of the sheet was caught on a stool. The throbbing thing seemed to fight its way toward that upraised edge. Suddenly the sheet sagged. Whatever had been trapped was trapped no longer. It seemed to Lane that its whining became a sound of maniacal fury. The Monster dived out of sight and moaned in terror.
Carol made a convulsive movement. Lane jerked his eyes to her. Her eyes were wide and terrified. Her mouth was open. She tried to gasp. She choked, suffocating, beating the air before her with her hands.
Lane plunged toward her, snatching up the cloth, which ripped because one of his feet was on it. He did not notice the resistance. He flung it over Carol’s head in instinctive use of the professor’s dictum that a sheet over one’s head would be sound sense at such a moment.
Then horror filled him. The sheet did not fall naturally about her. It draped over her head, but it enclosed something else. Something huge and invisible clung to her, whining and throbbing.
It was so completely revolting that at any other time Lane would have felt sick. But now he thrust out his hands. Something pulsating stirred his fingers through the cloth. He found Carol’s face while she struggled and put his hands together, scooping away the thing that clung to her. It filled a great part of the remains of the sheet. He clenched it tightly until he’d made the cloth into a bag whose neck he held fast. It was like a rubber balloon imprisoned in the sack, but no balloon ever fought against a cloth that held it, nor emitted a shrill bloodcurdling sound.
Lane’s hair felt as if it were standing straight on end, and horror flowed up his wrists from his hands and fingers. But he twisted the cloth, and twisted it again, compressing the captured tiling into a smaller and smaller space.
And suddenly there was nothing imprisoned in the cloth. It collapsed, and there was a reek of carrion in the air.
Professor Warren was pounding on his shoulders.
“Stop it! Stop it!” she cried furiously. Then she swore briefly. “Too late! You’ve killed it!”
Lane said thickly, “I’ll burn it—”
“Oh, Carol’s all right,” said the professor. “And it’s dead. But we learned some interesting items.”
“I’m going to make sure it’s dead!”
Professor Warren shrugged her shoulders. The Monster moaned and whimpered in his hiding place.
“Hush!” said Professor Warren angrily. She listened, with her head cocked on one side. There was a sound outside the trailer, now. It was a thin, high-pitched whine, save that it was made of many voices and was loud. It gave the impression of a frenzied anger shared by many things.
“Hm,” said the professor after a moment. “After all, it was a brilliant idea to insist that we close all the windows. It sounds as if our guest had friends, and they’ve come to help him or her or it to murder Carol.”
“How can I make sure this thing is dead?” demanded Lane. He still held the limp sack of cloth in his grip. But he was looking at Carol, who had buried her face in her hands.
“If,” said Professor Warren, with a fine air of competence, “if you took a jellyfish and put it in a cloth bag and twisted until you’d wrung the jellyfish out through the cloth, I don’t think you’d be worried about whether it was dead or not. That’s what you did with this thing.” She added exuberantly: “It was alive. It had a certain degree of intelligence. Perhaps a considerable degree. It’s amazing! And if you sniff you can’t help knowing something about its metabolism! No wonder the buzzards were temperamental! There were no smells for them to see!”
She stood still a moment, gloating over her discoveries. Then she moved to the other end of the living space and struck a match. She put water on the small, bottled-gas stove.
“For coffee,” she said beaming. “To celebrate. I’m going to make some notes while the water boils. Wildly imaginative, am I? I’ll show them some wild imagination! A dynamic system of gases, unquestionably living because it has undetermined but demonstrable intelligence, emotional reactions, and at least some degree of communication with its fellows! We irritated it and it called the others while it attacked! Let ’em try to classify a Gizmo like that!”