An ancient urn chained to a coffin is unearthed by chance by workmen alongside Rome's Viterbo Cemetery. Inside is an age-old tunic and artifacts that belong to Mater Lacrimarum (Moran Atias) - the Third Mother the only survivor of the Three Mothers, three powerful witches who for aeons have spread death and destruction throughout the city. The Mater has been hiding in Rome for centuries waiting for the moment when she will be awakened, triggering a chain of mysterious and terrible events.
Sarah Mandy (Asia Argento), a young student of restoration, co-worker and love interest of Michael Pierce (Adam James), the curator of the Museum of Ancient Art of Rome, is involved in the escalating and increasingly frantic episodes of violence. Sarah tries to run away but she cannot: the Third Mother is looking for her and Sarah is not aware of the fact that her mother Elisa Mandy (Daria Nicolodi) was a powerful white witch brutally killed by Mater Suspiriorum, the witch from Fryeburg.
Helped by the spirit of her mother, a priest (Udo Kier), by an eminent esoterism academic, Guglielmo De Witt (Philippe Leroy), and by the Chief Constable Marchi (Cristian Solimeno), Sarah realizes that she has no way out and that she must face the impending threat.