| Director | Montgomery Tully |
|---|
Musicals composer Norman Martell is having an affair with his wife Helen's divorced half sister, Peggy. Peggy repeatedly asks him to obtain a divorce and marry her; he finally agrees when she becomes pregnant. His wife refuses his request, partly because she still loves Norman, but also out of sibling rivalry, saying that their parents had always made her give way to Peggy's demands, but she would not give in to her this time. She suggests that the child's father may be someone else. Martell cannot just leave his wife, as she manages his royalty income. Instead, he plots her murder with Peggy, intending to use the tape recorder he uses in his composing to establish an alibi. Helen, however, has decided to allow the divorce, and goes to tell her sister, but when she goes to Peggy's house, she overhears their plans, and uses them to devise a murder plan herself.