Under the direction of the Lassan the ape-man took them each by an arm and led them back through the hall of the metal fish, down among the machines, where two or three others stared at them curiously or lifted inquisitive trunks in their direction. Then into another passage which had one of the inevitable car-tracks. Their Lassan conductor reached around the corner into the passage, applied his trunk briefly to something and a moment later one of the cars slid silently into position. The door opened. "So long, old scout," said Marta Lami. "Even if I never see you again, we had a great time together." "So long," replied Sherman, taking his place in the car. He felt a distinct pang at leaving this dancer--vulgar, no doubt, and flippant, but gay and debonair, and the best of companions. The car did not take them far. It discharged Sherman in a little passage before a narrow door, which opened automatically to admit him to a small blue-domed room containing nothing but a seat, one of the benches on which he had seen the Lassans reclining and a mass of wires and tubes. There seemed nothing in particular to do. He was at liberty, save that the door closed firmly behind him, cutting off escape, and seeing that he was left alone, he seated himself and began to examine the machinery, most of which was attached to his chair. CHAPTER XV The Lassan Explains Before he had time to riddle out any of its secrets the door opened again and one of the Lassans came in--a distinctly different type than any he had hitherto seen. This one was smaller than most; his skin, where exposed, was covered by a tracery of fine wrinkles and his coloring was whiter than the rest. Little crowfeet stood around the corners of his eyes, giving him an expression that was singularly humorous. He approached Sherman on noiseless feet, moved his trunk up and down as though examining him and then, producing from a pocket in his cloak one of the thought-helmets, set it on Sherman's head, tightened a connection or two with his trunk and placing a like device on his own head, settled himself on the twisted bench. The ordeal of the helmet! "They make you think whatever they want you to; it's like being hypnotized," Marta Lami had said. He braced himself resolutely. This alien intelligence should not plumb his thoughts without a struggle.... To his surprise, there seemed no attempt to force his mind. The thought leaped up, unbidden, "Why, this--this Lassan is friendly!" No definite image or plan or connection of ideas formed itself in his brain; he merely felt enormously soothed and strengthened. After all, he found himself arguing, nobody desired to hurt him; merely to discover what curious process of thought had led him to act as he had.