We’ve all seen some crazy stuff at the movies: razors to the eyeballs, butter and Brando, Linda Blair flying up to the ceiling, the careers of Peter Lorre and Klaus Kinski. But nothing quite tops the kinked-up horrors of Andrzej Zulawski, the understudied Paris-based Pole who also worked in English. You can’t quite believe what you’re seeing, not because what you’re seeing isn’t believable (although there’s that), but because you don’t believe you’ve really seen anything like it before — not this unrelentingly, at this runtime (two-plus hours).

Take 1981’s “Possession,” whose director’s cut the Harvard Film Archive is showing on Saturday and again Nov. 24 and 25. The movie is just about two people — Isabelle Adjani and Sam Neill, both young and dewy — getting a divorce. She’s found someone new. He’s upset. He spends the entire movie trying to get her change her mind. She spends most of the movie doing nothing terribly consistent — well, not nothing. Adjani was at the height of her impassive exotic-eroticism. Zulawski wanted the exotic and the erotic, just none of the impassive. It’s like watching a pond turn into a tsunami. Neill is just as devoted to the lunacy, slicing his arm with an electric knife, pacing until he all but burns tracks into the carpet.