Their carpeted way took them back to the entrance chamber and then up a steeply sloping corridor that led upward to the left. As they passed along they saw that the hand of a master had made on the walls, in panel effect, marvelously complicated decorations in many-colored mosaic. No man of Earth could ever have done such work, the two men realized--and this thought did not cheer them any. * * * * * At the top of their curving passage a doorway led them into a spacious room hung with soft, finely woven tapestries with a metallic lustre and furnished with deep-napped rugs and luxurious chairs and divans. Through this room the intangible threads of the alien will directed them--on into a wide-vaulted alcove about one-third its size. There, the strange clutch on them relaxed, and they looked about, at first apprehensively, then with growing boldness and curiosity. "This is the control room!" exclaimed Clee suddenly; and after a moment Jim agreed with him. It was the simplicity of the controls which had prevented them from recognizing it at first. Against the left wall was a great table with a tilted top, bearing, in its center, a raised and hooded eyepiece giving a view into a large, enclosed black box. On each side were several rows of small, shiny, metallic levers and what they took to be instrument dials--round, cup-shaped depressions with pointers free to move across dials lined with disorderly and meaningless convolutions. For the full length of the middle wall, straight ahead, was a broad table of some jet-black polished material, and on it was a large array of instruments and apparatus, all unfamiliar to them. Against the draperies of the wall to their right was one large cushioned chair, simple and beautiful in its lines. No living person or thing could be discerned in either the main room or the alcove. For several minutes the two men walked all about, examining everything they saw with curiosity and interest; and then Clee discovered a peculiar thing. His watch-dial, glowing very brightly now, would perceptibly increase in brilliance every time he neared the great chair. With sudden inspiration he took out his package of tobacco and held it in the line his watch made with the chair--and he found that his watch stopped glowing. He tried it again from another angle, and the result was the same. From that chair came the electrical disturbance that was making his watch-dial glow--yet nowhere near the chair was any bit of electrical apparatus to be seen. What he did see in the chair, though, almost caused his heart to stop beating. The cushions of the seat, compressed before, began to puff out to full volume, as if someone had just risen from them. And then, faintly but sharply outlined in the long-napped rug in front, appeared the print of a human shoe! "A man!" breathed Clee. "A human being!" * * * * *