In "The Films of Christopher Lee", the actor is on record as saying of the movie, "In my opinion, the best film Hammer ever made." He added that Seth Holt was "one of the best directors Britain ever had."
Sir Christopher Lee's most vivid recollection of this movie is, while shooting the dining room scene, suddenly realizing he was being observed by Gary Cooper. Director Seth Holt remarked that Lee looked as though he'd "seen a ghost." Cooper was shooting what was to be his last movie, La lame nue (1961), at the studio, and Lee recalls seeing Cooper having lunch every day by himself. The actor was suffering from cancer.
In March 2013, it was announced that this movie will be remade for Sony, and directed by J.A. Bayona, whose previous credits include the acclaimed Spanish horror movie, L'Orphelinat (2007).