Years before Scream, Italian horror came over all self-referential in this niftily nasty slice 'n' dice. The setting is one of those casually plush Roman cinemas that resemble nothing so much as a small opera house - sadly an exotic antique to the multiplex generation. Here teenage couples assemble to watch a creakily gothic Nostradamus flick, suck face and play pranks. And here it is they turn into cannabalistic demons, wreaking havoc worse than any exhibitor's grisliest nightmare. If great ideas made for great movies, this would be an all-time classic. Regrettably, it's a mediocre slasher with a terrific gimmick. The post-modernity extends off-screen: Dario Argento produced, and the director is the son of Mario (Black Sabbath) Bava. An inferior sequel followed.