Humanity has settled its first Jupiter-lunar colony. Rhonda is on the run after stealing a powerful political symbol. The Enforcers have sent a Hunter - a ferocious, relentless cyborg with whom Rhonda has a history - named Diarmuid to track her. That is, until the alien Guardian appears on the horizon. For the symbol in question is no a mere item. It needs to be returned to its resting place, before it is too late. Thief and Enforcer must now work together to save the colony.