his perspiration. It was hot on this accursed world—hot, muggy, dank. He kneeled over the water's surface. It looked pure, cool. A sudden thought struck him and he ripped a strip from his shirt and dipped it in the water. The plasticloth blackened and charred. He let it drop and the "water" quickly finished the job. Pool? No. Concentrated sulphuric acid or something just as destructive. Smiling grimly at his narrow escape, he wiped his perspiration with another strip torn from his sleeve and kept going. Several hours, at least, had passed since he had entered the strange world within the alien's mind. That meant one of two things: either the time-scale in here was different from that outside or his half-hour limit had elapsed in the outer world and Dr. Phelps had been unsuccessful in bringing him back. That was a nice thought. Suppose he was stuck here indefinitely, inside the mind of an alien being, in a muggy jungle full of sulphuric acid brooks? Well, he thought, I asked for it.... The stalemate couldn't continue indefinitely. If he had swallowed some of the acid that would have ended the contest without doubt; he wouldn't have had time to cope with the searing fluid. The answer lay there—surprise. Both he and the alien were mental entities who could do battle as they pleased—but in this conflict it was necessary to take the opponent by surprise before he could counterthrust or vanish. He began to see a solution. Up ahead lay the castle—unreachable, through some trick of the alien's. Very well. Harrell's brows drew together in concentration for a moment; his mind planned a strategy—and formed men to carry it out. There were six of him, suddenly. Six identical Harrells—identical in size, shape, form, purpose. They would attack the Dimellian simultaneously. Or, at least, five of them would, creating a diversionary action while the sixth—Harrell-original—made a frontal assault on the castle. Harrell-original faced his five duplicates and briefly instructed each in his job. They were like puppets. "Harrell-one, you're to attack in conjunction with Harrell-two, on the mental level. Take turns