A huge space station on the fringes of human space, SSS-900 is controlled by the brain of Simeon, a shellperson who relieves his daily monotony by replaying computer simulations of great battles. When a battered, jury-rigged ship appears to threaten the station, they rescue the people who are fleeing from the vicious Kolnari pirates. As the Kolnari take over the station, the stationers and the Bethelites from the rescued ship must devise ways to work together to fight the invaders. Luckily, Simeon's love of wargaming has unexpected uses, and he clandestinely builds his trap for the Kolnari. Will Simeon become the only thing standing between ruthless alien pirates and total destruction?