A small family in a lonely outpost on Mars is attacked by bandits. One of the bandits, Jerry, survives and kills the family father. He attempts to integrate into the family, demanding thirty days to prove himself to the surviving mother Ilsa and child daughter Remmy. Over time, Ilsa seems to warm to him, but after thirty days, Ilsa tries to shoot him. She fails as the magazine of the gun that Jerry intentionally left was empty, and Jerry kills her in the ensuing struggle. Remmy, who resents Jerry's presence, grows sullen and spends much of her time with "Steve", a pet-like robot found in a storage unit. Remmy also discovers that their farm is within a large force field bubble that keeps breathable air inside. This makes clear that the bandits came from outside or another similarly shielded area. Years pass, and Remmy, now a young woman, remains sullen and almost completely silent around Jerry. They have an argument over whether to have a child, and Remmy decides to run away, but Jerry stops her from doing so. He ties her up and attempts to rape her, but Steve blasts Jerry in the neck with its power-drilling attachment. Remmy frees herself and kills Jerry. Now alone, she decides to depart, leaving Steve to tend the outpost.
