While sightseeing at the Belmont Bevatron, Jack Hamilton, along with seven others, is caught in a lab accident. When he regains consciousness, he is in a fantasy world of Old Testament morality gone awry, a place of instant plagues, immediate damnations, and death to all perceived infidels. Hamilton figures out how he and his compatriots can escape this world and return to their own, but first they must pass through three other vividly fantastical worlds, each more perilous and hilarious than the one before.