50,000 years before the events of the novel, the planet Garth was leased to the Bururalli who, imperfectly uplifted, reverted to a pre-sophont state and nearly destroyed its ecosystem by overhunting all large indigenous species.

As the youngest clan in galactic civilization, Earthclan is mostly relegated to near-hopeless "recovery worlds" for colonization, and they are granted a lease to inhabit Garth.

The Gubru, a conservative and somewhat humorless alien race, decide to hold Garth hostage in an attempt to learn more about the discovery that the dolphin spaceship Streaker made in Startide Rising about the Progenitors.

The Gubru overpower Garth's token space forces, in the battle a neo-chimp soldier of Earthclan, Fiben Bolger, pilots a small craft that is damaged and crash lands in the mountains.

The Gubru, used to galactic norms, mistakenly believe that the neo-chimp population on Garth will be easily controlled without their human patrons to guide them.

Hoping to fool Kault with an elaborate and ultimately costly practical joke, Uthacalthing secretly instructs a furtive neo-chimp to create false evidence pointing to the existence of Garthlings – a fabled race of pre-sentient creatures that were rumored to have survived the Bururalli holocaust.

Fiben Bolger begins to fear that Earthclan's well-known naivete at Galactic punctilio could imperil the entire neo-chimpanzee population, both on Garth and on Earth.

The Suzerain of Beam and Talon orders his soldiers to destroy them, but they disobey and kill him, and the Gubru leave Garth in shame.