Fanatic (released in the United States as Die! Die! My Darling!) is a 1965 British horror thriller film directed by Silvio Narizzano in his feature directorial debut, written by Richard Matheson, and produced by Anthony Hinds for Hammer Film Productions. It stars Tallulah Bankhead (in her final feature film), Stefanie Powers, Peter Vaughan, Yootha Joyce, Maurice Kaufmann and Donald Sutherland.

Plot

An American woman, Patricia Carroll, arrives in England to marry her lover Alan Glentower. Before tying the knot, however, Patricia pays a visit to Mrs. Trefoile, the mother of her deceased fiancé Stephen, who died in an automobile accident several years earlier. Trefoile resides in a secluded house on the edge of an English village. She is fanatically religious, and it soon becomes apparent that she blames Patricia for her son's death. Indeed, when Patricia reveals to her that she never actually intended to marry Stephen, Trefoile enlists the aid of her servants, Harry and Anna, in holding Patricia captive so she can exorcise the young woman's soul. After several attempts to escape the Trefoile house, one of which nearly results in Patricia's being sexually assaulted by Harry, she is rescued by Alan; and in the end, Mrs. Trefoile winds up dead with a knife in her back, the same knife with which she earlier attempted to murder Patricia.