Christopher Lee's most vivid recollection of the film is suddenly realizing he was being observed by Gary Cooper during shooting the dining-room scene. Director Seth Holt remarked that Lee looked as though he'd "seen a ghost." Cooper was shooting his last film, The Naked Edge at the studio, and Lee recalls seeing him having lunch every day by himself as the actor was dying of cancer.
In 'The Films of Christopher Lee' the actor is on record as saying. "In my opinion, the best film Hammer ever made." He added that Seth Holt was ... one of the best directors Britain ever had."