 Much to his dismay, the script was altered to more closely resemble other Hammer movies.Although keeping the American protagonists, events were manipulated to allow the story instead to take place in an English country estate featuring a collection of stereotypical butlers, chauffeurs and curtseying maids.The Devil’s Doorway (Working)

Psychose (Alternative)

The Legacy of Maggie Walsh (Alternative)

Considered for Karl were Harry Andrews, Peter Cushing, Bernard Archard, Herbert Lom, Donald Pleasence, Sir Christopher Lee, Michael Gough, Anton Diffring, Peter Arne, Patrick Troughton, Peter Vaughn, and Donald Houston.