Evil lurks in the gloomy house at Markham Manor where a deranged Sir Edward is the chained prisoner of his brother Julian. When Sir Edward escapes, he embarks on a monstrous killing spree, determined to seek revenge on all those whom he feels have double-crossed him.
| Directing | Gordon Hessler | Director |
| Writing | Lawrence Huntington | Screenplay |
| Writing | Christopher Wicking | Dialogue |
| Production | Gordon Hessler | Producer |
| Production | Pat Green | Associate Producer |
| Production | Louis M. Heyward | Executive Producer |
| Sound | Harry Robertson | Original Music Composer |
| Camera | John Coquillon | Director of Photography |
| Editing | Max Benedict | Editor |
| Art | George Provis | Art Direction |
| Costume & Make-Up | Jimmy Evans | Makeup Artist |
| Costume & Make-Up | Bobbie Smith | Hairdresser |
| Writing | Edgar Allan Poe | Short Story |
