MacLean was awarded the Nebula Award for a short story with the same name, first published in Analog Science Fiction, March 1971. This novel is an expanded version of that short story.

From the DJ end-flaps: George Sanford has a gift for guessing right and very little else going for him. When Ahmed and his other friends in his gang grew up, they all advanced in school and got jobs, but George couldn't score well on tests, and there aren't any jobs for guys like him in The City. George never even wanted to sign his name, let alone fill in applications and reports.

When he bumps into his old gang leader, Ahmed, now a member of The City's Rescue Squad, George is swept up in the excitement of a hunt for a trapped girl. It is George who finds her with his special talent. George rapidly becomes the unconventional pride of the Rescue Squad. With Ahmed to run interference for him with the bureaucracy, George becomes a "consultant," and his talents grow. And George begins to change.

With each success he discovers more about himself and more about the society he lives in, and he begins to doubt. When a missing computerman's knowledge is put to use by an irresponsible gang of revolutionaries, threatening to destroy The City. George rescues the computerman and meets Larry, warped boy-genius and leader of the gang. But Larry asks questions George can't answer, and after Larry escapes, George knows he has to find him to continue the discussion. Only George is captured by Larry and forced to become a tool of Larry's mad iconoclasm. In Larry's control, George's talents pose the greatest threat of all to The City... George himself has become the missing man.