Demons

Lamberto Bava directed it, with Italian horror master Dario Argento producing and co-writing — Argento's involvement is a big part of the film's prestige among genre fans. Lamberto is also the son of legendary director Mario Bava, so the film carries a horror pedigree.

It takes place in West Berlin, where patrons at a screening in the Metropol cinema are given promotional masks — and then become demons, trapping the surviving audience inside the theater. The premise of a horror movie unleashing real horror on its own audience is the film's signature hook.

Yes, Demons 2 followed in 1986, again directed by Lamberto Bava and produced by Dario Argento, moving the demonic outbreak from a cinema to a high-tech apartment tower. Note that later films marketed as Demons 3, such as Michele Soavi's The Church (1989), were originally conceived in that lineage but are not true continuations.

Late in the film, two survivors ride a motorcycle through the theater's aisles slashing demons with a katana, one of the most iconic moments in 1980s Italian horror. The film's soundtrack of contemporary rock and pop, including tracks by Go West and Billy Idol-era artists, blaring over the carnage made the sequence legendary.