Constable Mike Boone never expected his quiet morning ride to investigate rumors of dead livestock to take a sharp turn into a war. Confronted by plasma rifle totting aliens he suddenly finds himself in a fire fight -- out gunned and outnumbered.Until then his quiet world was a quiet, backwater were nothing ever happen, yet to the large hungry aliens a frontier planet without a military looks like an invitation to lunch. Desperate to find a way to resist Boone enlists the aid of an old soldier banished to this world for his part in a bloody stellar conflict. Though on opposite sides two decades ago, the pair are forced to work together to foil the aliens. The situation becomes more complicated by the aliens' strange allies and their strange artifact. With battles raging in space and on the planet the action rushes to the furious climax when the neighboring human systems send a relief force.