The lady is Mrs. Hilyard, a wealthy poetess who lives in a three-story city mansion and her cage is her elevator, which stops a dozen feet short of the main floor due to an electrical failure on a July 4th weekend. She rings her outside alarm, eventually noticed by a drunken derelict, who breaks into the house, ignores her plight and helps himself to various items and alcohol. He leaves with his loot but returns a while later with a plump prostitute and three teenage hoodlums, who proceed to terrorize Mrs. Hilyard as they wreck her home.
When a young stranger enters a seemingly perfect family, the idyllic bubble they had been living in bursts and the chaos of the outside world infiltrates their lives, revealing their flaws, deepest fears, and dreams.