A unit of space marines is sent from Earth to a distant prison planet with which all contact has been lost. Upon waking from suspended animation, its members learn that their number includes a civilian, an employee of the company that runs the prison. After landing, they get involved in a shootout with some armed prisons and both sides suffer casualties. However, the marines learn that there was no uprising and that for the past three years the prison has been stalked by an invulnerable monster created by the company's biological experiments on the prisoners. The latter now have no option but to cooperate with the military in a desperate attempt to escape the planet after it is blown up with a nuclear device. A clone of ALIENS done on a tiny budget that works OK but fails to entertain.