The beginning of the film is very spoiled, and the parallel lines similar to "Psycho" symbolize the "cage"; the claustrophobia caused by the suspended elevator symbolizes the "cage"; the psychological torture of the intruder to the host symbolizes the "cage"; the underlying factor of the Idipas complex, the mother's control over the son also symbolizes the "cage"; the urban planning frame into the serious person, also framed the gangster, or "cage".