Ann Burden thinks that she might be the last person left on the planet because of a nuclear holocaust but then a man in the green plastic suit stumbles upon the girl’s valley. He takes off his suit for a swim but the water is radioactive so Ann tells him to get out, revealing herself.
Ann takes care of him and nurses him back to health and she persuades the man to move into her abandoned house. She isn't scared of him because he is very weak but she is happy to see another human.
Mr. Loomis gets healthier and starts pulling his weight like helping start the tractor again and helping out around the farm. Ann is very grateful to have a helping hand.
Mr. Loomis gets another fever and starts to become very ill again. When he gets better, he starts acting bossy and Ann gets uncomfortable.
After Mr. Loomis and Ann have a dispute, Ann decides to move back into her cave. She is growing fearful of Mr. Loomis, and is worried about his growing strength. When she goes back to the house to play piano for Mr. Loomis, he attempts to assault her. Now, not only is she living in the cave, but hiding there.
Mr. Loomis was sick of Ann staying away and not helping him anymore. He no longer likes the agreement of living separately and peacefully. So, Mr. Loomis shot Ann so that she would be wounded and to try and get her to stop the stupidity of staying away.