"Ignorance is never an excuse!" Tall-Thin's voice was a merciless rasp. "A well-organized logical mind does not make such mistakes. Now we are facing utter disaster unless we can get back to our home planet and warn _The Twenty_ that it would be sheer madness to attempt to colonize this planet again without better disease-preventing safeguards and atmosphere-resisting metals. Such safeguards can and must be worked out." Tall-Thin paused, watching Melvin as if apprehensive that the praise he was about to bestow would be held against him to the detriment of his vanity. "Unfortunately only two of us can go in this rocket, which has miraculously come into our possession. The primitive who constructed it, this Earth-child's progenitor, must have an almost Class B-type mind. Only two of us, understand?" "But--" "The survival of the wisest. I'm afraid I shall have to extinguish you, Rujit." The tube lit up again, so brightly that Tall-Thin's hand was blotted out by the glare. Equally blotted out was Rujit's face but the rest of him did not vanish immediately. One arm disappeared but not the other--and there was a yawning dark gap between his knees and his waist. It might not have seemed so horrible if Rujit had not shrieked first. The shriek had an outward-inward quality, echoing both inside the heads of the children and in the room as actual sound. Even Tall-Thin seemed shaken by it, as if in a race that had outgrown the need for physical speech there could be nothing more unnerving than anguish so expressed. Yet both the shriek and the almost instant blotting out of Rujit's face were eclipsed in point of horror by the fading of the little man's legs. They faded, kicking and protesting and spasmodically convulsed, faded in a ruby red glow that lingered for an instant in the still air like a slowly dissolving blood clot, then as slowly vanished. It was at that moment Mary Anne ceased to think as a child. She dug her knuckles into her mouth to keep from screaming but the undaunted way in which her mind worked was a tribute to her forgetfulness of self. _If he should do that to Melvin!_ Tall-Thin must have sensed the loathing in her mind, for he turned with a grimace of rage and trained the beam full upon her, taking care however to alter the tube's destructive potential with a quick twist of his thumb. "A primitive would have been sorely tempted to kill you, Earth-child," he said. "Fortunately for you we have a high and undeviating code of ethics." Back and forth over the children Tall-Thin played the beam, as if to make sure there would be no further unpleasantness from that source. Then he clicked off the tube again, and turned to his remaining companion--a little man who apparently believed that silence and good order were the foundation of all things.