When I reviewed Ari Aster's Hereditary last year, I called it “one of the most f*cked-up horror movies I've ever seen.” The same terminology could be used for his follow-up, Midsommar. Aster is working on a level few others are in the genre. This is art-horror at its finest. Imagine an Ingmar Bergman film with moments of graphic violence and freaky sexuality thrown in and you can begin to approximate what this extraordinary work is like.

Dani (Florence Pugh) and Christian (Jack Reynor) have been dating for four years. Their relationship is on the verge of falling apart. He thinks she's too needy; she worries about whether he's becoming tired of her neediness. After Dani experiences an unfathomable family tragedy, she decides to join Christian on a trip to Sweden, where he and his buddies Mark (Will Poulter) and Josh (William Jackson Harper) plan to observe a rural pagan community's mid-summer festival.

Midsommar pulls you in during the early scenes at their village. It looks like some kind of hippie commune, with everyone dressed in white linen and carrying out a series of very precise, elegant rituals against an idyllic Swedish backdrop. Something is happening under the surface, though, leading the film to become eerier as it progresses. Dani and Christian are invited to participate in the festivities. Hallucinogens are part of that, as is the witnessing of a ceremony that takes a brutal turn. To say anything too specific about what occurs would be to rob you of the story's surprises.

Midsommar is not just a “crazy cult” picture. What happens at this village reflects on Dani and Christian's strained relationship, as well as the trauma she has recently endured. The horror Aster creates isn't about blood and gore, although there are a couple moments of that. Instead, it's about how people can be susceptible to negative influences when they're already vulnerable. The central couple realizes that something untoward is going on among their hosts, yet they are seduced by the chance to witness something so few outsiders will ever get to see.

A major part of the film's effectiveness comes from the thoroughness with which Aster depicts the pagan society. There are very long, observant scenes of them practicing their customs. Taking the time to do that makes the community feel real for the audience. Consequently, the threat to Dani and Christian is increasingly palpable as those customs veer into uncomfortable territory. Superior production design and cinematography add exponentially to the impact. So does the fact that the entire story takes place during broad daylight, automatically allowing it to stand apart from the countless number of darkness-based horror movies.

Florence Pugh, who was so great earlier this year in Fighting with My Family, delivers a first-rate performance as Dani. The actress powerfully conveys her character's emotionally fragile state. In her hands, it's crystal clear how Dani finds herself drawn into the group's web. Nail-biting drama is achieved by making us wonder if she'll find her way out. Jack Reynor (Sing Street) matches Pugh step-for-step. He is required to execute some scenes in the third act that, done improperly, could have come off as ludicrous. Treynor keeps it real, to the movie's benefit.

Midsommar is unsettling throughout, and at times it's profoundly disturbing. There are no "Boo!" scares of the sort one would find in a Conjuring picture. No, this film does something more insidious – it gets under your skin with its themes and the way it contrasts the outer beauty of the pagan community with the ugliness inside.

Ari Aster is officially two-for-two in the “completely mess you up in the head” department.

out of four

Midsommar is rated R for disturbing ritualistic violence and grisly images, strong sexual content, graphic nudity, drug use and language. The running time is 2 hours and 27 minutes.