Suspiria (1977)

Suzy Bannion, an American ballet student from New York City, arrives late on a stormy night at the prestigious Tanz Dance Academy in Freiburg, Germany. While trying (unsuccessfully) to get someone to answer the door to the academy, she witnesses a young student, Pat Hingle, flee from the school. Suzy makes her way to a hotel, while Pat finds refuge at a friend's apartment in town. Pat tells her friend that she has uncovered something terrible inside the Academy, then locks herself in the bathroom. A shadowy figure appears outside the bathroom window – an arm smashes through the window and grabs Pat. Hearing Pat's screams, her friend runs for help but nobody answers. The attacker stabs Pat repeatedly – even once in her heart – and then slips a noose around her neck. The figure throws Pat through a window that leads into the apartment lobby below and the rope snaps, killing her, just as the falling glass kills her fleeing friend below.

Suzy returns to the academy in the morning and is introduced to Madame Blanc, the vice-directress, and Miss Tanner, one of the instructors. She is then introduced to students Sara and Olga, the latter with whom she has previously arranged to share an off-campus apartment. After a strange encounter with the academy's custodian, Suzy faints during a lesson. She awakens that night to discover that she has been moved into an on-campus dormitory, despite her reluctance. The doctors tell her that she is to be "medicated" with a glass of wine daily, and will have to live on campus for her continued care. Suzy rooms with Sara, and the two become friends.

As the students prepare for dinner, maggots rain down from the ceiling. The students are told this was due to spoiled food being stored in the attic and are invited to sleep in the practice hall overnight while the spoiled food and maggots are disposed of. During the night, Sara identifies a distinctive whistling snore as that of the school's director, who is not due to return to the academy for several weeks.

The following day, Tanner orders the school's blind piano player, Daniel, to leave the academy after his guide dog supposedly bites the custodian's son (who is also Madame Blanc's nephew). That night, Sara hears a teacher's footsteps and counts them whilst Suzy becomes drowsy and falls asleep. Elsewhere, while crossing a plaza, Daniel's dog and Daniel himself sense a strange presence before the canine – without warning – lunges at him and tears his throat out, killing him.

Suzy recalls that Pat had mumbled "iris" and "secret" when they briefly crossed paths. Suzy and Sara go for an evening swim at the school's indoor swimming pool and Sara reveals that Pat had been saying strange things for some time. The two girls search for Pat's personal notes, but they are missing. Suzy suddenly becomes drowsy again and falls asleep before Sara flees after hearing footsteps. Sara is chased by an unseen pursuer and, thinking she will be able to escape on a window ledge, falls into a pile of razor wire. She struggles until a dark figure slits her throat.

In the morning, Blanc and Tanner inform Suzy that Sara has abruptly left the academy. Confused and suspicious, Suzy goes to meet one of Sara's acquaintances in town, the psychologist Frank Mandel. Mandel explains that the academy was founded by Helena Markos, a cruel Greek émigré who was widely believed to be a witch, while Mandel's colleague, Professor Milius, tells Suzy that a coven can not survive without their queen.

Suzy returns to the academy to find that all the other students have been sent out for the evening to see a performance by the Bolshoi. After disposing of her food and wine (which may have been drugged, thus explaining Suzy becoming drowsy), she then hears the same footsteps that Sara heard, Suzy follows the sound to Blanc's office, entering to find the walls painted with the irises Pat had mumbled about. She finds a hidden passage and enters, quietly observing Blanc, Tanner and the staff performing a ritual and plotting Suzy's death. Suzy turns to find Sara's body nailed to a coffin. She sneaks into another room, where she accidentally awakens a shadowy figure who reveals herself as Helena Markos. Helena orders Sara's corpse to rise from the dead to murder Suzy, but Suzy stabs Helena through the throat with a knife she finds, killing Helena and causing Sara's corpse to collapse. The rest of the coven start asphyxiating without their queen, and Suzy escapes just as the academy collapses in flames.