Mrs. Hilyard, a wealthy poetess, resides in a three-story city mansion. Her elevator is her only means of transportation and stops at the main floor due to an electrical failure on July 4th weekend. She rings her outside alarm but it's noticed by a drunken derelict who breaks into her house. He 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.