The MacCollies have enjoyed a monopoly on interstellar travel for more than 200 years. Even Fleet--the military arm of the Fellowship of Humanity--has to use MacCollie drives and MacCollie-trained engineers to get starships from one planetary system to another. When an alien ship, with a totally different type of star drive is found by a small group of disaffected MacCollie engineers, they decide to learn the secrets of the alien drive and destroy the MacCollie monopoly. In doing so, they may shift the balance of power, and plunge the Fellowship of Humanity into an all-out civil war Pushing forward wth their unsavory goals, they recruit an ex-Fleet officer and try to use his training as an astrogator without ever telling him the truth about who they are and what their goals include. When he learns their secret, will he be able to stop them and save the Fellowship of Humanity for a cataclysmic end?