Dichronauts

Hugo Award–winning hard science fiction master Greg Egan returns with a new novel featuring one of science fiction’s most unusual worlds.

Seth is a surveyor, along with his friend Theo, a leech-like creature running through his skull who tells Seth what lies to his left and right. Theo, in turn, relies on Seth for mobility, and for ordinary vision looking forwards and backwards. Like everyone else in their world, they are symbionts, depending on each other to survive.

In the universe containi...