Demons

Demons is a 1985 Italian horror film directed by Lamberto Bava, produced and co-written by Dario Argento, and starring Urbano Barberini and Natasha Hovey. The plot follows two female university students who, along with a number of random people, are given complimentary tickets to a mysterious movie screening, where they soon find themselves trapped in the theater with a horde of ravenous demons.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

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