"Then you're my man," Dr. Gar said, giving him a deep look, "because I want you to go back in time and destroy humanity."
"Whatever you say." Roy's training showed. "But if I may comment, wouldn't that be superfluous? Except for you and me the human race is finished. We've achieved our objective." He spoke without irony.
"Never my objective."
"I'm not a scholar and I mean no offense," Roy said, "but I believe it was the co-ordinated spatial theory you announced back in '06 that made it possible."
"Misapplication," Dr. Gar said wearily, not wanting to go into it further for such an audience. Though, he thought, he'd never have another. "Come into my study and have your brandy."
"I still don't understand," Roy said later. He reached tentatively for the bottle. When the old man made no objection he poured a second stiff one.
"You want me to go back in time and wipe out all human life," Roy said. "I assume you'll tell me when and where. All right. That would destroy our ancestors and so we'd cease to exist, too. Wouldn't it be simpler to kill ourselves now? That is, if you see no point to our further existence."
Old Dr. Gar watched the other remnant of Earthly life twirl the brandy in the goblet. He looked at the viewscreen. It showed a panorama of rock dust and steam where Earth had been.
"You forget that we have annihilated everything," Dr. Gar said, gazing pensively at the screen. "Mankind, the animals, plant life and the tiny things that creep the earth or swim the waters. Your mission will be more selective."