This book is set in the science fiction world of the Star Frontiers game world. You are Ranger Chaylo, a human boy who is a member of a club called the Star Rangers. Your fellow rangers are other children, all of them alien. Rama is a female apelike Yazarian, Carrel is an insect-like Vrusk, and Gogol is an amoeba-like but intelligent, humanoid Dralasite. There is also Nanny Navigator Robot. The small white Boxils also appear in this book. These alien races are all frequently used in the Star Frontiers role-playing game, and the personalities of the Star Ranger children are, in a general sense, similar to the personality traits usually associated with their respecting species in the role-playing game. The goal of the story is to stop MR. Drel, one of your father's co-workers, from stealing an experimental starship and giving it to the Sathar, another popular Star Frontiers alien, who will then use it to invade other planets. The adults at Star Fleet do not believe the Star Ranger's warnings. Your father is also mentioned as being a scientist and a member of the United Planets, and the planet on which the book takes place is your home planet of Nedram.