The Valley
The valley represents a world unto itself, a microcosm of the world that used to be. It has its own water, wildlife, and natural resources - all of which remain relatively uncontaminated by the war. It is also a space that instead of being a place of safety turns out to be a place of danger for Ann, specifically after she runs away from Mr. Loomis. She cannot leave the valley because around it are radioactive lands. The valley is also her home, and she eventually ends up leaving it. In a sense she is not leaving the valley, or her home, but the world as she knows it. Whatever is beyond, including danger, is unknown, but as she has developed throughout the story it seems that she is willing to take on all of that.
The Safe Suit
The safe suit is the main source of contention between Mr. Loomis and his colleague Edward when they were fighting over whether Edward could use it to look for life. Mr. Loomis objected and eventually killed him. At the end of the story, Ann steals it from Mr. Loomis, and as she is walking away from him out of the valley, she expects him to shoot her. He does not. Whereas the suit was an object and site of danger and death for Edward, by the end, the suit has become an liberating object through which Ann is able to realize and pursue new possibilities, especially after overcoming Mr. Loomis and his objections.
Ann's Binoculars
Ann's binoculars are constantly a means through which she is able to acquire knowledge about Mr. Loomis, about her position in the valley, and about how to react to new situations. They are a kind of lifeline for her, and despite not being able to use them in certain situations (when it is too dark to see anything far in the distance, for example) they are a source of certainty and way to keep watch on Mr. Loomis. They are part of cool, calculated behavior and rational thinking, which she constantly uses to navigate and conceptualize ways of addressing new challenges. They represent a form of superiority and control over Mr. Loomis, because Ann remains informed of his movements, insofar as those movements are happening outside the house.
Staying Alive
Ann nurses Mr. Loomis back to life. Mr. Loomis impresses his authority upon Ann because he wants to plan for the long term and eventually create a thriving colony. The desire to stay alive is constantly putting both characters in danger, particularly Ann, and also constantly generating lethal possibilities. Survival governs their lives to the point that Ann is willing to risk herself entirely when she leaves the valley; she would rather live a shorter, more meaningful life than a mundane or dangerous one that involves Mr. Loomis.
The Tractor
The tractor is a constant site of contestation, of attempts at domination, of maintaining the possibility of life (by using it to farm), and even of facilitating death (when Mr. Loomis uses it to come after Ann in order to discover her hiding spot and shoot her). When Mr. Loomis removes the ignition key, he is reformulating the relations of power between himself and Ann because Ann needs to ask him for the keys, whereas before she could go straight to work. By slowly depriving Ann of her power, her resources, and her dignity and patience, Mr. Loomis attempts to establish his authority over her. The tractor is a particularly effective means of doing so, as Ann uses it to farm. Mr. Loomis takes the risk of not having the crops planted and soil tilled (because Ann does that) so that he can break Ann's spirit. Eventually Mr. Loomis is unsuccessful, but the tractor still serves as a useful way to contest Ann's perceived stubbornness and subordinate her.
