Applauded and hailed as one of the best films by the giallo master, Dario Argento.

A young woman enters an exclusive dance academy the same night that one of her students is murdered. The assistant director of the establishment is the kind Mrs. Blank, who provides the new student with all the comforts and facilities so that she can study and learn. But little by little an unhealthy air invades the place and her stay becomes a true nightmare.