What metaphors are used in Among the Brave by Margaret Peterson Haddix?

Much of the narrative is literally and metaphorically tied to bravery and determination. Bravery becomes an issue for Trey early in the book because others think of him as brave and he doesn't see himself in that light. As the group arrives at the Talbot house, Trey is sent inside. He says that he'd done one brave deed and that everyone is now expecting bravery from him. Trey's idea of bravery isn't practical but he's basing it on very limited experiences.