Soltan Gris is a member of the Voltar Confederacy, an expansionist alien empire of over a hundred worlds that regularly conquers new planets according to its ancient Invasion Timetables. Specifically, Gris works for the Coordinated Information Apparatus, Voltar's supposed intelligence section that consists of the worst self-serving scum and murderous villains in the entire Confederacy. One day Gris screws up and lets a Fleet survey report slip through unedited, bringing the planet Blito-P3 to the attention of Voltar's government. They learn that this "Earth" is a world under threat by its inhabitants' reckless pollution, which would render it unsuitable for conquest in a hundred years.
Voltar's solution is to send the renowned and decorated Combat Engineer, Jettero Heller, on a covert mission to save Earth by introducing green technologies, a mission that Gris joins as Heller's handler. But the head of the Apparatus, Lombar Hisst, has his own sinister interest in Earth, and wants to maintain the status quo there so he can use Earth's resources - specifically its drug supply - to take over the Confederacy. Will the duplicitous and conniving Gris succeed in undermining Heller's mission to fix Earth and help his boss take over the Confederacy, or will the heroic Fleet commando manage to save both worlds?