These creatures were the result of Hawk Carse's desperate search. They had composed, with one other, the band of isuanacs that had been rooting in the swamp at the end of the lake when the asteroid had first arrived. The Hawk had remembered them, and had quickly seen that they were the only answer to the problem. And so, with Ban Wilson, he had gone out for them, his mind steeled to the ghastly thought of the great scientists' brains in such bodies. In space-suits they had swept down on them. There had been no time for considerate measures: the four isuanacs had been abruptly knocked out by the impact of the great suits swooping against them, and carried back to the laboratory. Eliot Leithgow had been shocked at the idea of a scientist's brain in the head of the robot-coolie; how much greater, then, was his horror when confronted by the need of using these appalling remnants of men! But he could not protest. What else was there? Ku Sui, under the V-27, had spoken the truth: the operations would be impossible without the aid of his four assistants. The brains even now were dying. The choice was: bodies of isuanacs or death for the brains. The scientist and the adventurer had chosen. Circumstances had required their use. Ku Sui's attempt to kill the brains, thus inflicting a time limit: the presence of the band of isuanacs near the laboratory; each circumstance with a long train of other, minor ones behind it. Chance or Fate--whatever it is--whether predetermined or accidental--men must wonder at its working, and know awe from its patterns and results. Seldom, certainly, was there a pattern more strange than this now being worked out in the laboratory of Master Scientist Eliot Leithgow. The bodies lay there, washed, shaved and swathed in customary loose operating garments: globules of etheloid dropped steadily down into the breathing cones, of hunchback, living skeleton, twisted giant, dwarf and robot-coolie. One by one the isuanacs dropped with the falling of the etheloid into unconsciousness--and that was their farewell to the brains, each one debauched either by isuan-drug or skill of genius, that they had known. And movement began in the laboratory. White-clothed figures, masked and capped, used gleaming instruments in their gloved hands; and all the figures were mute--mute from their great concentration on the delicate work in progress--or mute from horror that would not die.... * * * * * So began the ordeal.