In a Q&A after a screening of his terrifying debut Hereditary, director/writer Ari Aster said that he was planning another horror movie. Now, only a year later, we see that what he had in mind was Midsommar.

In contrast to Hereditary’s shadowy interiors, housing inner darkness, domestic claustrophobia and disintegration, the horrors of Midsommar play out in glowing colours in the sun-drenched open-air.

Aster’s leisurely unfolding mystery takes place in a picturesque, tranquil commune in Hälsingland, nestling in the hills of northern Sweden. Here the Hårga people are celebrating a midsummer festival that occurs once every 90 years - a nine-day feast in observation of the summer solstice, when the sun never sets.

However, the film begins in the wintry gloom of America where Dani, (Florence Pugh), a graduate student, is beginning to panic as a family emergency spirals into her worst nightmare.

In the aftermath of intense tragedy, she seeks solace from her boyfriend Christian (Jack Reynor). Dani is conscious that she has made a habit of leaning on him throughout their four-year relationship, perhaps too much.

Distraught by grief she nevertheless begins to wonder whether he isn’t growing weary of her neediness. Christian is certainly being pressured to dump Dani by his laddish pal Mark (Will Poulter), who isn’t happy about her monopolizing Christian’s time. More indifferent are his other buddies, anthropology student and academic rival, Josh (William Jackson Harper) and Swedish exchange student Pelle (Vilhelm Blomgren).

Christian, feeling some sense of obligation, balks at breaking up with Dani during the height of her grief and instead asks her to tag along when Pelle invites the group to visit his ancestral village in Sweden, much to the chagrin of Mark, who had plans for a hedonistic lads’ outing.

When the group arrives in Hälsingland, they meet other guests, Connie and Simon (Ellora Torchia and Archie Madekwe) who have been invited from the UK by Pelle’s brother Ingemar (Hampus Hallberg). All are immediately introduced to the community’s particular skill with magic mushrooms and unusual ‘herbal teas’.

The Hårga welcome their foreign visitors, encouraging them to join in their celebrations but offering no explanation about the festivities each new day will bring. In contrast to Mark’s lust-fuelled explorations, it is the ancient customs, art and artifacts of the isolated community that spark the interest of Christian and Josh, creating a testy academic rivalry. Meanwhile, the ever-present sunlight and disorienting effects of various natural ‘preparations’ exacerbate uncontrollable and overwhelming surges in Dani’s grief.

The folkloric practices, if odd and quaint, start off innocuously enough, but the visitors quickly become stupefied by the constant sunlight and regular consumption of hallucinatory ‘teas’, and the village rituals become increasingly mesmeric and bizarre.

Although the community appears helpful and understanding regarding the relative freedom that the foreigners are allowed, their guests do not behave in a reciprocally considerate manner. Josh pursues the elders with questions then secretly disregards their pleas for secrecy as he attempts to further his own agenda, while Mark blunders around seeking his own gratification. This appears to be a critique of male entitlement and American crassness (Mark literally pissing on a foreign culture).

Dani is an outsider at first, tagging along with the male buddies, feeling disconnected and isolated in her grief, despite her smiles and protestations of feeling ‘fine’. As the days progress they all succumb to the dreamy weirdness of their location.

The physical and emotional chasm between Dani and Christian increases, as the disinterest and self-absorption of her long-time boyfriend become evident. The mutual empathy, support and interdependence of the community Dani finds herself in, though unnerving, becomes strangely beguiling, as the sterility of her relationship with Christian and with her family begins to dawn on her.

Ari Aster gets a quietly intense and astonishingly nuanced performance from Florence Pugh as the grieving Dani (his second fearless female lead after Toni Collette). Both his films provide dark comedy and a fascination with obscure pagan cultures, but predominantly deal with the harrowing emotional and psychological repercussions of trauma, loss and abandonment.

As in Hereditary, there is a ‘shocker’ moment near the beginning of Midsommer, but to be honest, visceral though it is, this time the viewer has a pretty good idea of what is likely to happen, and it doesn’t carry quite the same gut-punch as in the earlier film.

In fact, much of the unfolding horror in Midsommar is telegraphed to viewers ahead of time; some of it depicted in detail in the tapestries and murals which decorate the walls of the commune’s few buildings.

Aster and his production designer, Henrik Svensson, approach this fictional cult with meticulous anthropological detail. They lay clues for the audience as much as for the characters, while delighting in the fact that we have to keep watching to try to make out quite what is happening - observing the ceremonies and feasts, contemplating the runes and paintings while continuing to remain oblivious.

Pawel Pogorzelski’s dazzling cinematography and beautifully framed tableaus, Bobby Krlic’s unnervingly dissonant score and Andrea Flesch’s repetitive, pure-white Nordic-embroidered costumes, immediately establish a creepy sense of being trapped in a zone beyond time and logic.

The foreign location, language, dress and (fictional) customs will undoubtedly reinforce the American idea that old Europe (Scandinavia in this case) is weird and full of ancient, alien rituals which cannot be understood or trusted. (Though interestingly, weird cults are far more common in America, as European cults mostly preferred to relocate to the New World to ‘do their thing’ unhindered).

Garnering inspiration from classic folk horrors such as Ben Wheatley’s Kill List and Robin Hardy’s 1973 pagan-cult classic, The Wicker Man, Midsommar is not out and out scary, opting instead for a sense of mounting unease, shockingly punctuated by scenes of dizzying weirdness and visceral brutality.

Eschewing all the tired conventions of horror, Ari Aster offers an original, visually gorgeous approach to creeping dread - he continues to be a refreshing new voice in horror cinema. Midsommer is bright, dreamy and hypnotic, yet with the subtle visual and emotional power to unsettle the steeliest of viewers.