The research ship "Brozok" with a team of 150 intelligent dolphins, 7 people and one intelligent chimpanzee, finds an abandoned fleet of spaceships - each the size of a small moon. Perhaps they belong to the Progenitors, a legendary alien race that first began to sow intelligence among the stars, and then disappeared without a trace. With information about one of the most important discoveries in the galaxy, the "Brozok" becomes a target for several fleets of extraterrestrial civilizations and crashes on the unknown water planet Kitrup. While in space alien armadas unleash a real war in the struggle for the knowledge of the Progenitors, the crew of the "Brosk" finds out that Kitrup is a very strange world. Its fauna is extremely hostile, and in the vast depths there are many secrets that can forever turn the history of the entire inhabited cosmos.