Winner of this year’s Palme d’Or at Cannes, The Square is a daring sociological satire that sends up, among other things, a modern preoccupation: political correctness. Swedish writer-director Ruben Ostlund creates an ingenious high-wire act putting bourgeois beliefs and interpersonal trust to the test, while the audience is kept off-balance watching ideals clash with moral relativity and self-interest.

The tale revolves around Christian (Claes Bang), the tall and stylish chief curator of contemporary art for X-Royal Museum in Stockholm. Christian’s arrogance is matched with an ivory tower social conscience, and thus he has installed “The Square.” Outside the museum, a historic monument of a monarch is replaced with the conceptual art piece, a 4×4 meter illuminated chalk outline on cobblestones called a “sanctuary of trust and caring,” where anyone who asks for help should (presumably) receive it.

Behavior is under the microscope within the museum as well. A sign asks those who mistrust people to turn left and those who trust people to turn right.  Those who go right are then instructed to leave their wallet behind in a designated space. During an artist Q&A, a Julian Schnabel-type (Dominic West), clad in pajamas, is heckled loudly and repeatedly by a man with Tourette syndrome yelling obscenities. Discomfort hangs in the air as the hosts are too stunned to do anything but carry on and pretend they don’t hear the incessant interruptions.

In the very first scene, an American journalist (Elizabeth Moss) interviews Christian, and their chemistry is obvious. When she recites back to him some of his catalog text, she learns from his response that though he is is well versed in the wordy theorizing of so-called “art speak,” he can just as easily reverse himself and criticize what he said as pretentious drivel. Later, the two go to bed after celebrating the museum’s seasonal opening and end up tussling over the used condom in a left-field post-coital moment. His silent fears are matched with her unspoken dare, to trust her with its disposal.

The film’s pivotal storyline revolves around a pickpocketing maneuver that prompts Christian to consider how far he will go for restitution. In a crowd of morning commuters, he and another passerby come to the aid of a women crying out to be saved from a threatening man. Before the smugness from his magnanimity fades, he finds that his phone and wallet disappeared during the altercation.

He recruits one of his younger employees (Christopher Læsso) to brainstorm retrieving the missing items, which they locate to a large, low-income apartment complex, via a “Find My Phone” app.  A letter will be slipped under the door of all residents with a request that the belongings be brought to the 7-Eleven at the train station. Christian is emboldened by his plan, though he assumes his colleague will do the legwork of going from apartment to apartment to deliver the letters while he waits in his Tesla in the gang-filled neighborhood, but his employee demurs and ends up driving the car around to avoid gun shots while Christian delivers the letters.

At his initial stop at the 7-Eleven, with his cash gone the way of his stolen wallet, Christian uses credit to buy a sandwich for a homeless woman—the chicken ciabatta she asks for—but Christian either forgets or ignores her request for “no onions.” Later, an angry child from the apartment complex leaves a message at the 7-Eleven. He is upset that his parents erroneously think he is the culprit indicated in the letter slipped under their door. “Apologize, or I’ll make chaos for you,” is his demand, but Christian is already in over his head.

In the most cringe-inducing set piece, what appears to be the entertainment at a formal museum dinner becomes an increasingly alarming scene of primal instinct, as a performance artist, imitating an ape, crosses the line into actual animal behavior. The muscular he-man (stunt double and motion-capture veteran Terry Notary) moves instinctively like a simian, jumping on tables, groping and grabbing a woman as the stunned patrons sit dumbfounded.

Ostlund’s previous four films unnervingly mined similar behavioral territory. His last work, Force Majeure (2014), examines the role of masculinity when a man abandons his wife and children at sight of an avalanche falling during a family ski trip. His breakout, Play (2011), focuses on black and white teenage boys in Gothenburg and an elaborate scam.

Rambling in parts, The Square is a sprawling film at nearly two and a half hours and not as cohesive as it could be. Some episodes shine while others could have been cut. Nevertheless, it is a must-see as a sometimes brilliant commentary on class, privilege, and decency. It will have you pondering its significance weeks afterward.