The Mote in Time's Eye

Shangrin was the captain of the most advanced starliner of a thousand thousand centuries from now. His vessel was between the Magellanic galaxies when it became a casualty of a war between the ultimate powers of the Last Days. But far from being destroyed, Shangrin's vessel became the digit that threw off everyone's calculations. And Shangrin himself, determined to return home to his own time and sphere, refusing to be a pawn for sacrifice, took his own hand in the cosmic game.