A well-handled, absorbing post-nuclear-holocaust yarn, from the up-and-coming author of Startide Rising. After a limited nuclear and biological war, society has degenerated into hundreds of isolated, suspicious, often hostile communities. Gordon Krantz, ex-militiaman, now a wandering actor and storyteller, comes upon a dead mailman; having just been robbed by bandits, Gordon gratefully takes the dead man's uniform. Then, at the next village, the people believe he's a real mailman--so Gordon invents a story about a new US arising in the east, of which he is the first representative. He even agrees to carry some letters when he leaves, and even manages to deliver some of them, but his mere appearance is enough to rekindle hope in many of the struggling communities. Later, wandering in Oregon, he discovers a community that still has work-able technology and even some repaired video games. The society is run by Cyclops, a state-of-the-art Artificial Intelligence that's somehow survived from prewar days. And Gordon's mail-hauling duties continue to expand, as he reestablishes post offices, carriers, and routes; after a while the idea, which Gordon himself hardly believes in, becomes self-perpetuating. Then he discovers that Cyclops is a fake too: the computer didn't survive, but the idea persists as a kind of oracle run by a handful of surviving scientists. And there are further complications in store, as an army of insanely vicious, slave-taking survivalists threatens to invade. As a writer, Brin isn't quite fully mature yet: there are a few false-sounding passages, and the emotional tone is uncertain at times. Still, this hard-cover debut is a highly persuasive, often gripping, and warmly involving odyssey.