The Cyber Prime had a problem. The vast combination of disembodied intelligences he controlled was in trouble. There was a solution, but it remained as an equation in the mind of just one man, the wanderer Dumarest. And Dumarest hated the Cyber...

The Cyber Prime weighed the known factors of Dumarest's movements, his desperate questing efforts to find the lost Earth. An answer came up: Dumarest must arrive on the world Tynar. The Cyber mobilized to intercept him there. But the girl Eloise intercepted him first. And she was the random factor that the Cyber had not counted upon.