In this wry, paranoid vision of the future, overpopulation has turned cities into cramed industrial anthills. For those sick of this dystopian reality, one corporation, Trails of Hoffman, Inc., promises an alternative: Take a teleport to Whale's Mouth, a colonized planet billed as the supreme paradise. The only catch is that you can never comeback. When a neurotic man named Rachmael ben Applebaum discovers that the promotional films of happy crowds cheering their newfound existence on Whale's Mouth are faked, he decides to pilot a scapeship on the eighteen-year journey there to see if anyone wants to return.

It is a tale of revolution, of the rebellion of a former penal colony on the Moon against its masters on the Earth. It is a tale of a culture whose family structures are based on the presence of two men for every woman, leading to novel forms of marriage and family. It is the story of the disparate people, a computer technician, a vigorous young female agitator, and an elderly academic who become the movement's leaders, and of Mike, the supercomputer whose sentience is known only to the revolt's inner circle, who for reasons of his own is committed to the revolution's ultimate success.

Douglas Quail, a simple and ordinary clerk, wishes to visit Mars. Unable to afford it, he visits a company, REKAL (pronounced "recall") Incorporated, which promises to implant an "extra-factual memory" of a trip to Mars as a secret agent. The procedure involves administration of narkidrine, a sedative and truth drug, which causes Quail to remember and reveal that he actually did go to Mars as a secret government agent. His conscious memories of the trip have been erased, but his initial desire to sign up for the trip cannot be removed. The REKAL staff quickly get Quail out of their office without implanting anything, but his real memories are now returning slowly. At home, he finds physical evidence to support his trip but also remembers that he attended REKAL. This conflict causes him to angrily return for a refund, which he is given.