Sako, the captive, was sullen and restless, and made furtive glances at the Hawk, who stood detached, arms hanging carelessly at his sides, gray eyes half closed, giving in his attitude no hint of the strain the others were feeling. But his attitude of being relaxed and off his guard was deceptive--as Sako found out. Suddenly his left hand seemed to disappear; there was a hiss, an arrowing streak of spitting orange light; and Sako was gaping foolishly at the arm he had stealthily raised to one of the radio switches. A smoking sear had appeared as if by magic across it. Hawk Carse sheathed his gun. "I would advise you to try no more obvious tricks," he said coldly. "Cutting in our microphone is too simple a way to give warning to Dr. Ku Sui. Move away from there. And don't forget your lines when Dr. Ku calls. You will never act a part before a more critical and deadly audience." Sako mumbled something and rubbed his arm. A pitying smile came to Friday's face as he comprehended what had happened. "You damned fool!" he said. * * * * * It was 10:22 P.M. Still, in the visi-screen, no other ship. Nothing but the giant planet, the smaller satellites poised against it, and the deep star-spangled curtain of black space all around. They had carefully followed the instructions in the log. They were at the exact place noted there: checked and double-checked. The radio receiver was tuned to the wave-length given in the log. But of Ku Sui, nothing. And yet, in a way, he was with them. His enigmatic personality, his seldom-seen figure was very present in their minds, and with it were overtones of all the diabolic cunning and suave ironic cruelty that men always associated with him. "He comes out of darkness, out of empty space...." Friday licked his lips. He was not built for mental strain: his lips kept drying and his tongue was as leather. A little sputtering sound tingled the nerves of the three waiting men, and as one their eyes went to the radio loudspeaker. A contact question was being asked in the usual way: "Are you there, Judd? Are you there, Judd? Are you there, Judd?" The voice was not that of Ku Sui. It was a dead voice, toneless, emotionless, mechanical. "Are you there, Judd?" it went on, over and over. "The mike switch, Friday," the Hawk said, and then was at Sako's side, his ray-gun transfixing the man with its threatening angle. "Play your part well," was the whisper from his lips. The switch went over with a click. Trembling, Sako faced the microphone. "This is Sako," he said. "Sako?" the dead voice asked. "I want Judd. Where is Judd?" "Judd is dead. The trap failed, and there was a fight on Iapetus. Judd was killed by Carse, and most of the others. Only two of us are left, but we have Carse and the negro, prisoners, alive. What are your instructions?" A half minute went by, and the three men hardly breathed.