Knowing well that conversation with its fellows is one of the greatest needs of any intelligent being, the Nevians had permitted the Terrestrial specimens to retain possession of their ultra-beam communicators. Thus it was that Costigan had been able to keep in touch with his sweetheart and with Bradley. He learned that each had been placed upon exhibition in a different Nevian city; that the three had been separated in response to an insistent popular demand for such a distribution of the peculiar, but highly interesting creatures from a distant solar system. They had not been harmed. In fact, each was visited daily by a specialist, who made sure that his charge was being kept in the pink of condition.
As soon as he became aware of this condition of things Costigan became morose. He sat still, drooped, and pined away visibly. He refused to eat, and of the worried specialist he demanded liberty. Then, failing in that as he knew he would fail, he demanded something to do. They pointed out to him, reasonably enough, that in such a civilization as theirs there was nothing he could do. They assured him that they would do anything they could to alleviate his mental suffering, but that since he was a museum piece he must see, himself, that he must be kept on display for a short time. Wouldn't he please behave himself and eat, as a reasoning being should? Costigan sulked a little longer, then wavered. Finally he agreed to compromise. He would eat and exercise if they would fit up a laboratory in his apartment, so that he could continue the studies he had begun upon his own native planet. To this they agreed, and thus it came about that one day the following conversation was held:
"Clio? Bradley? I've got something to tell you this time. Haven't said anything before, for fear things might not work out, but they did. I went on a hunger strike and made them give me a complete laboratory. As a chemist I'm a damn good electrician; but luckily, with the sea-water they've got here, it's a very simple thing to make...."
"Hold on!" snapped Bradley. "Somebody may be listening in on us!"
"They aren't. They can't, without my knowing it, and I'll cut off the second anybody tries to synchronize with my beam. To resume—making Vee-Two is a very simple process, and I've got everything around here that's hollow clear full of it...."
"How come they let you?" asked Clio.
"Oh, they don't know what I'm doing. They watched me for a few days, and all I did was make up and bottle the weirdest messes imaginable. Then I finally managed to separate oxygen and nitrogen, after trying hard all of one day; and when they saw that I didn't know anything about either one of them or what to do with them after I had them, they gave me up in disgust as a plain dumb ape and haven't paid any attention to me since. So I've got me plenty of kilograms of liquid Vee-Two, all ready to touch off. I'm getting out of here in about three minutes and a half, and I'm coming over after you folks, in a new, iron-powered space-speedster that they don't know I know anything about. They've just given it its final tests, and it's the slickest thing you ever saw."
"But Conway, dearest, you can't possibly rescue me," Clio's voice broke. "Why, there are thousands of them, all around here. If you can get away, go, dear, but don't...."
"I said I was coming after you, and if I get away I'll be there. A good whiff of this stuff will lay out a thousand of them just as easily as it will one. Here's the idea. I've made a gas mask for myself, since I'll be in it where it's thick, but you two won't need any. It's soluble enough in water so that three or four thicknesses of wet cloth over your noses will be enough. I'll tell you when to wet down. We're going to break away or go out trying—there aren't enough amphibians between here and Andromeda to keep us humans cooped up like menagerie animals forever! But here comes my specialist with the keys to the city; time for the overture to start. See you later!"
The Nevian physician directed his key tube upon the transparent wall of the chamber and an opening appeared, an opening which vanished as soon as he had stepped through it; Costigan kicked a valve open; and from various innocent tubes there belched forth into the water of the central lagoon and into the air over it a flood of deadly vapor. As the Nevian turned toward the prisoner there was an almost inaudible hiss and a tiny jet of the frightful, outlawed stuff struck his open gills, just below his huge, conical head. He tensed momentarily, twitched convulsively just once, and fell motionless to the floor. And outside, the streams of avidly soluble liquefied gas rushed out into air and into water. It spread, dissolved, and diffused with the extreme mobility which is one of its characteristics; and as it diffused and was borne outward the Nevians in their massed hundreds died. Died not knowing what killed them, not knowing even that they died. Costigan, bitterly resentful of the inhuman treatment accorded the three and fiercely anxious for the success of his plan of escape, held his breath and, grimly alert, watched the amphibians die. When he could see no more motion anywhere he donned his gas-mask, strapped upon his back a large canister of the poison—his capacious pockets were already full of smaller containers—and two savagely exultant sentences escaped him.