- Published: 1970
- Nebula Award for Best Novel, 1971 —
- Locus Award for Best Novel, 1971 —
In answer to an unanswerable future, science has created Bohn, the omnipotent computer whose flashing circuits and messianic pronouncements dictate what tomorrow will - or will not - be. But Matthew Oliver is flesh and blood and full of questions - not nearly as certain as the machine he's appointed to serve. And the right hand of science seldom knows what the left hand is doing . . .