A witch burned at the stake curses her accusers, Lord Jeffreys (Cihangir Gaffari), Lady de Winter (Karin Field) and her lover Renfield (Alberto Dalbes), and she proclaims as she burns that her daughters will fulfill the curse. Alarmed, Lady de Winter sets out with Renfield to find the girls, Margaret (Britt Nichols) and Kathleen (Anne Libert), tracing them to a convent where they have become nuns. Once at the Blackmoor Nunnery, Mother Superior (Doris Thomas) tells Lady de Winter that she has had her eye on 2 nuns in particular who appear to have impure thoughts. Upon closer inspection Lady de Winter finds out Kathleen is not a virgin and proceeds to move her to a castle where she is tortured. Lord de Winter (Howard Vernon) frees Kathleen from her torture, but Lord Jeffrey's gives Renfield, who was wrongly accused of freeing Kathleen, 3 days to find her. The fun only begins there though as Margaret soon finds herself possessing the evil that "invaded" her body one night…