THE MOTHER OF TEARS

Catholic Church workers dig up the body of a 19th-century church official, whose casket has a box-shaped urn chained to it. Inside they discover artifacts of Mater Lachrymarum, the last surviving member of the Three Mothers, an ancient trio of powerful witches. The box contains a magic tunic that, when worn by Mater Lachrymarum, increases her powers significantly.

The urn is shipped to the Museum of Ancient Art in Rome, where Sarah Mandy, an American studying art restoration, works. Sarah is dating the curator Michael Pierce, a single father who is away from the museum that night. With help from the assistant curator Giselle, Sarah opens the box and finds the tunic. While Sarah is retrieving translation tools from her office, Giselle is attacked by the demonic agents of Mater Lachrymarum. Sarah returns to find Giselle disembowelled and tries to flee the museum. She is pursued by Mater Lachrymarum's familiar, but manages to escape when a disembodied voice guides her through locked doors that are magically thrown open.

Sarah tells the police what happened, then spends the night with Michael and his son. Meanwhile, in her lair, Mater Lachrymarum dons the tunic. The next day, Michael visits the Cardinal who sent the urn to the museum, but the Cardinal has had a severe stroke and is now comatose. Michael is given a message the Cardinal had been writing when he collapsed; the paper contains the scrawled name "Mater Lachrymarum." A pair of witches observe Michael as he leaves.

In Rome, chaos descends as a wave of mass suicides, murder, and violence engulfs the city. After his son is kidnapped by witches, Michael contacts Sarah. Sarah begs him to call the police, but Michael refuses and instead plans to visit a local priest who is an exorcist. En route, Michael is captured and murdered by the witches. His captive son is killed and cannibalized by the rapidly expanding coven.

As she makes her way through a train station, Sarah is spotted by a gang of witches who have arrived in Rome in order to pledge their loyalty to Mater Lachrymarum. Pursued by the witches as well as police detective Enzo Marki, Sarah escapes when the disembodied voice from before teaches her to make herself invisible.

Sarah meets Marta, a white witch and friend of Sarah's deceased mother Elisa. Marta realizes that the disembodied voice guiding Sarah is Elisa, who was herself a powerful white witch. Elisa challenged and severely wounded Mater Suspiriorum, the eldest and wisest of the Three Mothers, who retaliated by causing the crash that killed Sarah's parents. Though Mater Suspiriorum was killed by Suzy Bannion, a ballet dancer in Rome and her sister Mater Tenebrarum was killed by Mark Elliott in New York, Mater Lachrymarum aims to bring about the second age of magic, with the fall of Rome being her first goal.

Sarah returns to her home in the city but observes Mater Lachrymarum's forces waiting for her. She heads for Marta's house and discovers Marta and her lover murdered. Fleeing, Sarah spots Michael, who takes her back to his apartment. Sarah soon realizes that Michael is a corpse being animated by Mater Lachrymarum. Sarah burns Michael's animated body, and the ghost of her mother intervenes one final time to banish Michael to Hell.

Sarah locates De Witt, an alchemist whom Marta mentioned as someone who could help her against Mater Lachrymarum. De Witt gives Sarah a copy of "The Three Mothers" to read, enabling her to find Mater Lachrymarum's lair. Enzo Marki, the police detective who has been tailing Sarah, joins her to venture into the catacombs where Mater Lachrymarum's cult lurks. Enzo is separated from Sarah and captured and tortured, along with De Witt. Sarah is caught and brought before Mater Lachrymarum, who is wearing the ancient tunic. Sarah heals Enzo's wounds and uses a spear to pull the tunic off Mater Lachrymarum. She tosses the tunic into a nearby brazier, causing the lair to collapse and a pillar to impale and kill Mater Lachrymarum. With the followers crushed as the catacomb collapses, Sarah and Enzo struggle back above ground and laugh in horror and relief.

Sarah confronts and defeats Mater Lachrymarum, ending the witch’s reign of terror and restoring order to Rome.

The film climaxes with Sarah embracing her psychic heritage to battle the Mother of Tears, symbolizing the final chapter in Argento’s trilogy. This not only resolves the immediate threat to Rome but also closes the saga of the Three Mothers, bringing personal and supernatural closure to Sarah and the series as a whole.