Writer-director Ari Aster's debut film, 2018's "Hereditary," was a two-hour masterclass in the sustainment of dread, a festering concoction of stark, soul-rattling drama and unholy pagan horror diving headfirst into a family's disintegration. His sophomore feature, "Midsommar," provocatively delves into a different kind of dissolution: that of a wilted romantic relationship long past its expiration date. Playing upon certain folk-horror conventions of "The Wicker Man" variety, Aster has made a less fiercely unpredictable picture but one which is no less disquieting. "Midsommar" is a spellbinding two-and-one-half-hour dance through a sunlit nightmare, steadfastly haunting one's mind in its brazen aftermath. At every turn, there is one certainty: the audience is in the hands of a true artist, standing head and shoulders alongside the most exciting voices currently working within this genre.

"Midsommar" begins in the snowy dead of winter. It's a season reckoned with unimaginable loss for Dani (Florence Pugh), a college student who, in one catastrophic fell swoop, has her parents and mentally ill sister stripped from her. With the arrival of summer comes a chance at renewal, or so she hopes. When Dani learns boyfriend Christian (Jack Reynor) and his friends, Josh (William Jackson Harper) and Mark (Will Poulter), are planning to tag along with Swedish student Pelle (Vilhelm Blomgren) as he returns to the rural commune where he grew up for a nine-day solstice festival, Dani decides a sojourn may be just what she needs to break free from her grief-stricken reality. For the American visitors, entering into this cultural celebration of religious ritual and pageantry begins as an entertaining curiosity—and for Christian and Josh, a potential subject for their at-odds theses. In a place and time of year where the sun never fully sets, however, prying eyes are met at every turn. As the commune's customs take an unthinkably horrific turn, Dani finds herself in a harrowing situation in which there may be no escape.

In "Midsommar," a young woman struggling to pick up the pieces following personal tragedy runs afoul of an increasingly frightening circumstance attuned to take advantage of her trauma-based vulnerabilities. Witnessing Dani and her fellow travelers march toward destinies they could never have anticipated is much like a procession entering into the belly of a smiling, sinister beast. That Dani should not be there—she is only going to this remote corner of northern Sweden because Christian is, and, unbeknownst to her, her boyfriend has wanted to end their four-year relationship for quite a while—is both the cruel punchline and something of fateful symmetry. Director Ari Aster and cinematographer Pawel Pogorzelski are our guides into this unhinged world of inverted mores, the camera unnervingly flipping upside-down during one mesmerizing shot to follow the protagonists as they drive to their destination. Pogorzelski's vivid lensing of a deceptively peaceful day-bleached sanctuary is nothing short of hypnotic, at once idyllic and tenebrous. Bobby Krlic's music score and Henrik Svensson's production design are perfection, too, in their ability to appear docile yet unconscionably threatening.

Taking a spiritual page from Toni Collette's towering performance in "Hereditary," Florence Pugh (2019's "Fighting with My Family") is almost supernaturally sublime in the emotionally demanding lead role of Dani. Portraying a character overcome with anguish and anxiety long before she boards a flight to Sweden, Pugh wholly embodies the ordeal of a person trying to keep herself together while facing an uncertain future with an uncertain support system. Hers is a complex turn of raw, unshakable empathy, culminating in a quaking catharsis of moral and psychological ambiguity.

Whether Dani recognizes it or is merely in denial, her connection to longtime boyfriend Christian has been frayed for a long time. One senses early on they are together out of a combination of obligation and fear of change; indeed, Christian is seen attempting to muster up the courage to end things when the worst news possible strikes Dani. Unsuspectingly attending this festival, then, may be a calamitous decision for both, but it also works as catalyst for shaking them out of their stagnant status quo. Jack Reynor (2016's "Sing Street") effectively plays Christian as likable and selfish in equal measure, a guy guided by wants and desires that could prove his undoing.

For viewers well-traversed in the cinematic subgenre of folksy isolated communities and the guests who come to wish they hadn't interloped, "Midsommar" leads to a destination of hair-raising inevitability. At every step, Aster is in such fine control of his mise en scene the act of watching the film starts to emulate the psychotropic influence the characters are under. An enduringly intense experience though the picture is, there is a gentle, intoxicating fluidity to its tempo and pacing, a luciferous (and Luciferous) glint tricking all involved into a state of submission. What becomes of Dani and Christian and Josh and Mark happens while they're already in the center of the maelstrom, and by then there's only surrender. "Midsommar" is a renaissance of the macabre, a cinematic symphony of lulling, twisted goodbyes and portentous shadows in the blistering light of day. Once it latches on, there's no breaking away.