Trying to figure out which of Roman Polanski’s films are or are not “horror films” is a maddening and, in the end, fruitless exercise. Like Alfred Hitchcock, Polanksi gleefully dances around the darker edges of what might normally be termed “thrillers,” and he often brings the tropes and techniques of horror films to material that has nothing whatsoever to do with the supernatural. But I think it’s safe to say that his two movies about the Devil—or, more accurately, about people being somehow terrorized by Satan and his minions—fit the bill. Rosemary’s Baby (1968), about a young pregnant couple (John Cassavetes and a brilliant Mia Farrow) whose co-op board turns out to be a Devil-worshipping cult, helped kick off a decade’s worth of Satanic-possession movies. Some 30 years later, Polanski returned to tales of the infernal with The Ninth Gate (1999), which stars a wonderfully deadpan Johnny Depp as a rare-book dealer who stumbles into a search for a tome purportedly written by the Devil himself.

<a href="https://moma.org/explore/inside_out/author/csilver" target=blank">Charles Silver</a>, the organizer of MoMA’s current Roman Polanski retrospective, says of Polanski’s 1976 chiller The Tenant, “[The film] oscillates between Kafkaesque horror and surreal humor.” This accurately describes a significant number of the director’s films, but it absolutely nails Polanski’s “Devil movies.” In both films, an increasingly isolated individual must navigate a spiraling descent into the uncanny—but also into the gleefully absurd. Rosemary Woodhouse’s situation is unquestionably terrifying: Satan is very interested in her unborn child, which is certainly no laughing matter. And yet Polanski gives us plenty to laugh at, from the very notion of a cabal of urban geriatric Satanists to several wry jabs at the “cult” of parenthood itself.

Rosemary’s Baby is well established as a cinema classic, but I submit that The Ninth Gate—which divided what little audience it had, and scores an anemic 42% Rotten Tomatoes critic rating (the true filmic barometer of our time!)—is Polanski’s most underrated film, in part because it is ostensibly a horror film. Now hear me out. The most common knocks against the film basically boil down to “ludicrous” and “not scary.” Taken at face value, The Ninth Gate must plead “guilty” to both charges. Appreciated for its absurdist comic elements, however, it is an often brilliant success. The film’s various occultists and Satanic minions are, on the whole, bumbling idiots; Dean Corso (Depp) remains unflappable and utterly unimpressed even when it becomes apparent that he’s looking for a book written by Satan, and even after he is menaced by a burning woman in a wheelchair. Yes, you read that correctly. It’s like Laurel and Hardy Meet the Dadaists.

If you haven’t seen Rosemary’s Baby, I can only assume that you scare easily or you’ve been living in a cave. But if you, like most people, haven’t seen The Ninth Gate—or if you did see it, and didn’t quite care for it—perhaps it’s time you gave the Devil his due.

Rosemary’s Baby screens at MoMA on September 10 and 24; The Ninth Gate screens on September 16 and 29.