NEW YORK (CNS) — All dressed up as slow-moving psychological horror, "Midsommar" (A24) relies on the stale trope of feckless naive visitors to a primitive tribe that specializes in unnatural practices.

That writer-director Ari Aster makes the setting an ostensibly whimsical Swedish commune does nothing to mask his story's descent into crude sexploitation.

It takes a long time to get there — to pad a chiller out to 140 minutes requires a lot of al fresco banquets in the perpetual sunshine of Scandinavian summer attended by twinkly-eyed bearded men, sturdy buxom women and the occasional young seductress. But the terror, the sex and the gore eventually rush in on cue, even though they carry little shock value given the predictability of it all.

College student Dani (Florence Pugh) is already emotionally needy, made more so by the suicides of her only sister and both parents. Boyfriend Christian (Jack Reynor) is perpetually on the verge of breaking up with her, and his friends urge him to dump her.

So what better way to rekindle their relationship than with a trip to what they think is a Swedish festival in the company of Christian's graduate-school pals Josh (William Jackson Harper), Mark (Will Poulter) and Pelle (Vilhelm Blomgren)? There's some by-golly good thesis writing to be done there about Scandinavian pagan religion, these fellows conclude.

"It's been 90 years since our last great feast!" proclaims Siv (Gunnel Fred), a sort of a high priestess. That's the first clue, along with a sinister yellow pyramid to which entrance is forbidden, plus a bear in a cage.

Even the giant maypole ceremony has ugly connotations. And the commune, we learn, avoids inbreeding by the occasional use of unwilling outside participants. When members get past age 70 and are no longer able to work hard (or, presumably, dance), there's a rite in which they pitch themselves off a tall cliff to their doom.

One by one, the visitors are either picked off or assimilate themselves to the commune's menacing activities. Who gets to become the May Queen? The answer is not surprising.

It's just another sensationalist trip into the realm of savagery, with no redeeming features.

The film contains warped moral values, bloody violence, human sacrifice, strong sexual content, including aberrant behavior, an explicit encounter and full male and female nudity, drug use, a few profanities and pervasive rough language. The Catholic News Service classification is O — morally offensive. The Motion Picture Association of America rating is R — restricted. Under 17 requires accompanying parent or adult guardian.