Frank Singuineau

American tourists David and Jack are savaged by an unidentified vicious animal whilst hiking on the Yorkshire Moors. Retiring to the home of a beautiful nurse to recuperate, David soon experiences disturbing changes to his mind and body.

Loner Mark Lewis works at a film studio during the day and, at night, takes racy photographs of women. Also he's making a documentary on fear, which involves recording the reactions of victims as he murders them. He befriends Helen, the daughter of the family living in the apartment below his, and he tells her vaguely about the movie he is making.