'Collateral'

Sometimes dictionaries help. Consider the title of the movie "Collateral." I worked myself into knots over the title until I consulted a dictionary or three. The noun "collateral" didn't make much sense here. The phrase "collateral damage" helped, but it still had holes. Look at the meanings of the adjective. The physical idea in the adjective "collateral" assists greatly in the interpretation. See the elevator scene. And note the position in which Cruise and Foxx sit in most of the scenes.

OK. The following definition was also useful: "secured or guaranteed by additional security, especially by personal as opposed to real property."

Never, never, never involve yourself in literary criticism.