During the War, a British agent travels to the remote Glennye Castle in the wilds of Scotland to investigate a mysterious murder by a masked phantom. Who or what is the phantom? And how are the Germans involved?
Unfortunately the movie Castle Sinister is not yet available on HBO Max.
| Directing | Oscar Burn | Director |
| Writing | Vance Youden | Theatre Play |
| Writing | Mary Cathcart Borer | Screenplay |
| Production | William Howard Boer | Producer |
