Set in the Paris of 1996, “Climax” opens with a flash-forward to a scene that won’t make sense until we’ve seen the entire film, followed by the scroll of credits we normally see at the end of a movie, followed by a tedious and static sequence featuring videotaped interviews with each member of a newly formed hip-hop dance troupe.

The group includes lead dancer Selva (Sofia Boutella), arguably the most grounded and likable member of the team, and David (Romain Guillermic), an insatiable Lothario whose reckless womanizing will earn him multiple enemies; the German dancer Psyche (Thea Carla Schott), who says she had to get out of Berlin because of all the drug abuse, and the father-figure DJ everyone calls Daddy (Kiddy Smile).

Cut to this group of young and wildly talented performers executing a dance number in a cavernous gymnasium in an apparently abandoned school.

It is a jarring, beautiful, dangerously adventurous symphony of arms and legs and torsos, bursting with originality and sexuality and almost violent physicality, all set to a relentless and seemingly endless hip-hop beat.

Seriously great stuff.

Finally, though, the music comes to a stop, if only for a moment, and the sweat-soaked dancers applaud one another and then split off into groups of two and three as they down cups of sangria and celebrate their upcoming tour in an all-night party hosted on that very same dance floor by their beloved manager Emmanuelle (Claude Gahan Maull).

Gossip abounds. Petty jealousies are expressed. Trusts are broken. Rivalries are established. We learn about a number of complicated romantic entanglements. It’s clear the teamwork displayed during that dance number is pure illusion.

Turns out this might be more “Lord of the Flies” than “Lord of the Dance.”

And that’s about the time we learn someone has spiked the sangria with LSD, igniting an all-night, horror-show rave in which the dancing never stops, even as various characters commit unspeakable acts against one another.

“Climax” turns into a sick circus of atrocities, set to the pulsing beats of everything from Daft Punk to Soft Cell. All of a sudden, we’re in a depraved zombie movie — with a beat. The blood flows and bones break as nearly everyone surrenders to their darkest instincts.

Writer-director Noe assaults our senses with his usual artistic flair, whether it’s the absurdist storyline or the attention-getting lighting, a series of ALL CAPS title cards inserted into the heart of the movie, dizzying camerawork that sometimes invokes Kubrick and Scorsese, but just as often is more annoying and attention-seeking than dramatically effective, and the increasingly absurdist storyline.

Alas, with the notable exception of the empathetic Boutella, the cast of “Climax” consists primarily of dancers who are not actors.

And as actors, they’re really good dancers.