Through the darkened rooms of the old mill in Dunwich, a tiny island off the New England coast, a shuffling figure creeps towards a sleeping child. In a nearby bedroom, Sarah Whately (Carol Lynley) and her husband Luther (Rick Jones) are roused by the sounds.
Luther reaches the child, his four-year-old niece Susannah (Anita Anderson), and wards off an attack by the shadowy figure. Desperately, he drags the creature back to the shuttered room at the top of the house and firmly bolts the door.
Several years later, Susannah (Carol Lynley again) has grown into a beautiful woman and returns to the isolated community of Dunwich with her husband Mike (Gig Young), where they meet Ethan (Oliver Reed), Susannah’s surly arrogant young cousin who warns them to stay away from the mill.
But they are determined to look over their inheritance and enter the dark, dirty place. Memories begin to rise in Susannah’s mind and she feels uneasy.
Ethan comes to the house and tells them Aunt Agatha (Flora Robson) – now the oldest surviving member of the Whately family – wants to see them.
They meet the strong-willed old aunt only to receive more warnings. But nevertheless, they still move into the mill, where they become involved in a new episode which is even more terrifying.
Despite the American location of the movie (adapted from a story by HP Lovecraft), filming took place on location in England – in Kent and on the Norfolk coast. The burning of the old mill at the end of the film involved an actual old building (Hardingham Mill in Norfolk) which the production company purchased specifically to destroy.
Although the mill had fallen into disuse and was derelict, the building was something of an ancient landmark in the area, and the local population protested but to no avail.
Mike Kelton
Gig Young Sarah Whately/Susannah Kelton
Carol Lynley Ethan Whately
Oliver Reed Aunt Agatha
Flora Robson Emma
Judith Arthy Luther Whately
Rick Jones Mary Whately
Ann Bell John Whately
Robert Cawdron Zebulon Whately
William Devlin
Donald Sutherland (voice) Barge Master
Charles Lloyd Pack Tait
Bernard Kay Aunt Sarah
Celia Hewitt Gang Members
Murray Evans
Cliff Diggins
Peter Porteous Susannah as a Child
Anita Anderson
Several years later, Susannah (Carol Lynley again) has grown into a beautiful woman and returns to the isolated community of Dunwich with her husband Mike (Gig Young), where they meet Ethan (Oliver Reed), Susannah’s surly arrogant young cousin who warns them to stay away from the mill.
Despite the American location of the movie (adapted from a story by HP Lovecraft), filming took place on location in England – in Kent and on the Norfolk coast. The burning of the old mill at the end of the film involved an actual old building (Hardingham Mill in Norfolk) which the production company purchased specifically to destroy.
Although the mill had fallen into disuse and was derelict, the building was something of an ancient landmark in the area, and the local population protested but to no avail.
Ethan Whately 
