The story arises from the murder of Rikaine Delmarre, a prominent "fetologist" (fetal scientist), responsible for the operation of the planetary birthing center of Solaria, a planet politically hostile to Earth, whose death Elijah Baley is called to investigate, at the request of the Solarian government.

He is again partnered with the humanoid robot R. Daneel Olivaw, and asked by Earth's government to assess the Solarian society for weaknesses.

The only witness is a malfunctioning house robot that has suffered damage to its positronic brain because it allowed harm to be done to a human, in violation of the First Law.

She reveals to Baley that she does not like all the customs of Solaria, where face-to-face interaction, and especially sex, are considered repugnant, and was on bad terms with Rikaine, partly from sexual frustration.

Ultimately, it is revealed that Delmarre's neighbor, roboticist Jothan Leebig, was working on putting positronic brains in spaceships.

Leebig had instructed one of the Delmarre house robots to detach an arm and give it to Gladia in the heat of an argument.

The lack of cooperation between them discourages an active, exploratory attitude that Earth-born humans will eventually rediscover once they are able to leave Earth.

[3]: 136 Baley, however (while traveling in a closed vehicle because of his own agoraphobia, resulting from his life in the enclosed cities of Earth), insists on face-to-face conversations.

The novel was adapted for television as an episode of the British anthology series Out of the Unknown, with Baley being portrayed by Paul Maxwell and Daneel by David Collings.

Broadcast on BBC2 on 18 February 1969, the story was dramatised by Robert Muller and directed by Rudolph Cartier and the music and sound effects were created by Delia Derbyshire of the BBC Radiophonic Workshop.

[4] In 1978, the novel was adapted in the Soviet Union under the name "The Last Alternative" (Последняя альтернатива) In 2023, a Persian translation of the book was published in Iran.