Russ nodded grimly. His thumb tripped the tele-transport control and from the engine rooms came a drone of power. In Ranthoor Prison, great bands of force wrapped themselves around the vault, clutching it, enfolding it within a sphere of power. Back in the _Invincible_ the engines screamed and the vault was ripped out of the solid steel wall as easily as a man might rip a button from his shirt. _CHAPTER FIFTEEN_ John Moore Mallory sat on the single metal chair within his cell and pressed his face against the tiny vision port. For hours he had sat there, staring out into the blackness of space. There was bitterness in John Moore Mallory's soul, a terrible and futile bitterness. So long as he had remained within the Ranthoor prison, there had always been a chance of escape. But now, aboard the penal ship, there was no hope. Nothing but the taunting reaches of space, the mocking pinpoints of the stars, the hooting laughter of the engines. Sometimes he had thought he would go mad. The everlasting routine, the meaningless march of hours. The work period, the sleep period ... the work period, the sleep period ... endless monotony, an existence without a purpose. Men buried alive in space. "John Moore Mallory," said a voice. Mallory heard, but he did not stir. An awful thought crossed his mind. Now he was hearing voices calling his name! "John Mallory," said the voice again. Mallory slowly turned about and as he turned he started from his chair. A man stood in the cell! A man he had never seen before, who had come silently, for there had been no screech of opening door. "You are John Moore Mallory, aren't you?" asked the man. "Yes, I am Mallory. Who are you?" "Gregory Manning." "Gregory Manning," said Mallory wonderingly. "I've heard of you. You're the man who rescued the Pluto Expedition. But why are you here? How did you get in?" "I came to take you away with me," said Greg. "Back to Callisto. Back to any place you want to go." Mallory flattened himself against the partition, his face white with disbelief. "But I'm in a prison ship. I'm not free to go and come as I please." Greg chuckled. "You are free to go and come as you please from now on," he said. "Even prison ships can't hold you." "You're mad," whispered Mallory. "Either you're mad or I am. You're a dream. I'll wake up and find you gone." Manning stood in silence, looking at the man. Mallory bore the marks of prison on him. His eyes were haunted and his rugged face was pinched and thin. "Listen closely, Mallory," said Greg softly. "You aren't going mad and I'm not mad. You aren't seeing things. You aren't hearing things. You're actually talking to me." * * * * * There was no change in the other's face.