Wealthy widow Helen Mercer hires a young woman, Gretchen Addison, to act as her personal assistant and companion. Unfortunately, Helen is a poor judge of character, as Gretchen is part of a murderous extortionist duo with her boyfriend, Jay. However, Gretchen has second thoughts when she develops genuine affection for Helen. When Gretchen informs Jay that she wants to call off their plot, he refuses and carries on with the plan. Now both Helen and Gretchen may be in grave danger.
Unfortunately the movie Betrayal is not yet available on HBO Max.
| Writing | Doris Miles Disney | Novel |
| Writing | James M. Miller | Teleplay |
| Directing | Gordon Hessler | Director |
| Sound | Ernest Gold | Original Music Composer |
| Camera | Jacques R. Marquette | Director of Photography |
| Editing | John A. Martinelli | Editor |
| Camera | Robert Blair | Key Grip |
| Sound | John Mick | Music Editor |
| Editing | Robert Papazian | Supervising Editor |
| Production | Joe Wonder | Production Manager |
| Editing | Scott C. Eyler | Assistant Editor |
| Production | Elliot Friedgen | Production Executive |
| Production | Eddie Foy III | Casting |
| Costume & Make-Up | Gertrude Wheeler | Hairstylist |
| Directing | Mary Yerke | Script Supervisor |
| Production | Gerald W. Abrams | Associate Producer |
| Production | Gerald I. Isenberg | Producer |
| Costume & Make-Up | Marie Brown | Costumer |
| Art | Sam Bergman | Property Master |
| Art | Solomon Brewer | Set Decoration |
| Production | Charles W. Fries | Executive Producer |
| Directing | Maury Dexter | Assistant Director |
| Production | Jerry Wineman | Location Manager |
| Sound | Charles T. Knight | Sound Mixer |
| Sound | Robert J. Litt | Recording Supervision |
| Costume & Make-Up | Fred B. Phillips | Makeup Artist |
| Lighting | Robert A. Petzoldt | Gaffer |
