A remote mining settlement on a distant planet has gone silent, prompting a military response from the Colonial Marines. When the soldiers arrive at the abandoned colony, they uncover a horrifying truth: the facility has been overrun by a terrifying extraterrestrial organism that reproduces through parasitic means. The few colonists who haven't been killed have been transformed into vessels for the creature's reproductive cycle, leaving the marines to confront both the aliens and the grim fate of the colony's inhabitants.