The singing sound. As he walked back along the corridor, it diminished. He turned and retraced his steps. The sound greatened until he came to an archway in one wall of the corridor. The sound obviously emanated from that direction. The archway was supported by gleaming marble pillars and as Tommy passed between them, the singing sound rose to a crescendo that vibrated deliciously against his nerve centers. Then he saw it. A beautiful, domed room that gave a first impression of being a public bath of some sort. But there was no water, only brilliant, breathtaking color; all the gorgeous colors of the rainbow dancing down from the ceiling in beams of crystal clarity. There was sound and color—and something else; a subtle something that made Tommy very happy; excitedly happy in a way he had never before experienced. He moved forward, completely engrossed in his new surroundings. He moved in under the shower of color and a feeling of ecstatic exhilaration went through him. It was wonderful. Then he froze. Not twenty feet away stood two Martians clad in rich metal harness and holding long golden spears. Guards. Sudden fear swept Tommy. The Martians were staring straight at him. Desperately, he signalled to his frozen muscles; Let's get out of here. But they failed to respond. The guards stared at him. He stared back. Nothing happened. Why, they're asleep, Tommy thought in amazement. They're standing there sound asleep with their eyes wide open holding their spears. That's crazy. Why don't they fall down? Tommy wanted to run. But he couldn't. The curiosity of the very young not only barred retreat, but pushed him slowly forward until he was standing beside one of the guards. The Martian had not moved a muscle. His chest neither rose nor fell. Completely fascinated, Tommy extended his hand. He touched the face of the guard. It was rough and cool. The guard did not move, Tommy laid a hand against the golden harness. Nothing happened. He had not intended to push, but he did. He pushed so hard the guard tilted over on one stiff leg. Appalled, Tommy leaped back. The guard kept on tilting until he fell on his side with a great crash of ringing metal. Tommy darted back through the color rays and out of the strange room so fast that he was far down the marble hall before his mind told him he