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. ...
Wanting to build a family, a childless couple fosters a young orphan, survivor of a tragic childhood. But their act of love turns to horror when they find themselves besieged by a malevolent entity intent on destroying the new family.