Presently Hekki looked up, and as though moved by some intuitive realization that he was being watched, turned awkwardly in his cumbersome attire, and glanced along the row of portholes in the side of the vessel. He saw the Earthman and smiled at him. Shelby felt that it was the kind of smile which a tolerant father might show to his youngest son. Hekalu waved his hand, and his lips, behind the glazed front of the helmet, formed several words which Shelby could not interpret. Then the Martian returned his attention to his apparatus. * * * * * When Selba entered his prisoner's room some moments later, he found him lounging on the bunk. The Martian looked enquiringly at Shelby. "You have reached some conclusion, my friend?" he asked. Without changing his position on the bunk the young man nodded. There was an expression of dejection and sullen resignation on his face which he was trying hard, above the intense excitement which possessed him, to make realistic. Still acting the part he spoke: "Yes, Akar Hekalu," he said between teeth that were apparently gritted with rage, "I have decided to reveal to you the secret of the Atomic Ray." A triumphant gleam came into the Martian's eyes. "Ah, my friend," he said, "you at last see the light. I knew that you would. But what has been the cause for this sudden change in attitude? The torture chamber, perhaps?" There was an undercurrent of suspicion in Hekalu's voice. Shelby turned his head sullenly away, feigning shame. He said nothing. A minute passed during which time Hekalu stared at his captive, a sardonic smirk of contempt curling his thin coral lips. Finally he said, "I will have Koo Faya bring you writing materials, and you will describe in writing every detail of the manufacture of the missing element." "No," replied Shelby, turning his face toward the Martian, "I haven't the ability to do that. It will be necessary for you to take me to the laboratory of the ship where I can demonstrate the process to you. It is much too delicate and complicated." The noble's eyes wavered slightly. "Once," he said, "you tried to trick me, but I warn you that I am on guard now so do not attempt it again." He signed to Alkebar who had been standing silently beside the open door. The giant drew a key from a pouch at his side, and kneeling, unlocked the fetter fastened about Shelby's ankle. It rattled to the floor. And at the same time the Earthian, leaning back on the bunk with arms stretching over his head, tapped sharply three times with his signet ring on the power-pipe. It seemed to be only an unconscious gesture--nervousness perhaps. Immediately there was a terrific crash from down the passage way, followed by an agonized scream. Another crash. More screams.