This is the third book in David Brin’s Uplift series. In this book, a Human-Chimp outpost faces invasion by a superior species, the Gubru. The Gubru are after the location of a lost battle fleet found by a dolphin ship (book 2). After discovering that the dolphin ship is lost to the humans, they try to salvage their invasion to find some gain. Their efforts are hampered by a Tymbrimi ambassador and his daughter.
The fight takes a bit of an underground war flair, the Gubru are an occupational force. Some of the Chimps play a major role, as David Brin uses the events to explore their social structure. He shows us some interesting personalities in these chimpanzees.
The book also explores the Tymbrimi, one of the Humans few allies in the galactic confederation of bizarre species. The Tymbrimi have an odd culture that places great value in practical jokes. They use this skill in support of the Human position in the occupation.
Generally, the book is good, but not strong. It should be read as part of the series, but would probably not stand well on its own.