

Unbeknown to him and his colleagues, there is a base on the planet of an enemy of the League of All Worlds-a young world named Faraday, which embarked on a career of interstellar war and conquest, and which chose this "primitive" world as the location of a secret base. It was through Rocannon's efforts that the planet had been placed under an 'exploration embargo' in order to protect the native cultures. He later goes on an ethnological mission to her planet, Fomalhaut II. The novel then follows Gaverel Rocannon, an ethnologist who had met Semley at the museum. She returns to find her daughter grown up and her husband dead.

Due to relativistic time dilation while the trip will be of short duration for her, many years will elapse on her planet. Semley descends into their tunnels, uses the spaceship for the flight and returns after sixteen years. The interstellar League of All Worlds has placed an automated spaceship at the disposal of the more advanced underground dwellers of the planet. A young woman named Semley takes a space voyage from her unnamed, technologically primitive planet to a museum to reclaim a family heirloom. The novel begins with a prologue called "Semley's Necklace", which was first published as a stand-alone story titled "The Dowry of Angyar" in Amazing Stories (September 1964).
