"But why?"
"To help him save the Earth," the tall man said. "When it was destroyed originally, small colonies of us were stranded on inhospitable planets. We're still trying to crawl out of the decline that set in. But if we can send you back and save the Earth—well, you will remain with Paul Chandler. And we—?" He walked to a bank of controls near the door and put his hand on one. "Who knows? None of this will have happened. We might not even exist."
"Now," said the short man, joining the taller one, "we will have to wipe out all memories for you and tomorrow we will start programming you for another try. Maybe this time we'll try moving the Earth's orbit closer to the sun."
"Wipe out my memories?"
"Of course. We want you to function with a clear mind. Besides, it's kinder to you."
"I see." The mind named Chandler looked at the two men. "But please leave me with my memories just for tonight."
The tall man turned off the light. "You always ask that and we always do."