What metaphors are used in Bel Canto: A Novel by Ann Patchett?

In Chapter Four, a fog falls over the house, which makes it impossible to see anything outside. The fog intensifies the feeling of entrapment. and the characters inside feel as if time has stopped. In essence, the fog serves as a metaphor illustrates the way the characters perceive time. The fog is also a metaphor for confinement, as the the fog adds to the characters' feelings of isolation.