In the year 2489, on the ecologically wounded planet Garth, humanity's fragile Earthclan holds a lease to nurse a ruined biosphere back to health, a foothold resented across a galactic civilisation ordered by the ancient practice of Uplift, in which patron species raise clients to sentience. When the avian Gubru invade, hunting knowledge of the dolphin-crewed ship Streaker, they seize most of Garth's humans with a targeted toxin, assuming the neo-chimpanzees left behind will be helpless without their patrons. They are wrong. The colonist Robert Oneagle and the neo-chimp officer Fiben Bolger take to the hills to build a resistance, while the Tymbrimi girl Athaclena and her diplomat father Uthacalthing spin an elaborate deception to unbalance the occupiers. Brin, whose gift is for large casts, wry humour and the sheer texture of an invented ecology, writes adventure that keeps circling back to a serious question about power and stewardship, though the pacing is more leisurely than its predecessor. Beneath the chases and intrigue, the novel asks what patronage really means, whether uplifting a species is a gift or a subjugation, and how the weak outwit the strong.