In a fit of drunken bravado, Co-Navigator Anthony Troy tries a stunt to impress his date of the evening. While the rest of the ship parties away the Diamond Jubilee of the New Era, the duo soon find themselves in a terrible jam. Both get lost in space. It is then he also discovers that the lady in question is none other than the only daughter of Marshall Bingenbatten, the most powerful man in the Asteroid belt space stations. Though they are rescued by a near miracle, he flees to Mars, where the mutants are being dumped by the pure beings of Earth. There he is surprised to find these unfortunate victims of the nuclear holocaust are building a fleet to contest the Solar System. He joins them and both sides head for the climatic Battle of the Shepherd Moons, the most decisive battle in the history of the Earth.