When watching Sirāt in a cinema, you have to fight the urge to get up and dance. Like a cross between Mad Max: Fury Road and Climax, Óliver Laxe’s post-apocalyptic EDM thriller starts off with gigantic speakers laid out in a Moroccan desert like Jenga pieces. Plugged in, the sound system generates pounding techno for hundreds of blissed-out ravers to leap around as the sun sets upon the surrounding mountains. If the theatre’s volume levels are correct, the vibrations will be so powerful that it’s like 4DX. “Some critics watch a film with their brain,” Laxe tells me. “But this film has to be watched with the body.”

Laxe, a 43-year-old Galician director, is himself a raver, even if his passion for thumping electronica wasn’t so apparent in his earlier indies like Mimosas and Fire Will Come. “I did this film for young audiences,” he says. “When I go to a rave, I dance with that generation, even if I’m 10 or 20 years older.” He mentions that Sirāt is selling so many tickets in France, it’s going to outgross The Substance. “It’s thanks to young audiences going to the cinema because they feel represented. That doesn’t happen with arthouse cinema.”

The Arabic word “sirāt” translates to “the path” in English, and Sirāt soon reveals itself as a road movie. Amongst the revellers, two figures stick out in middle-aged Luis (Sergi López from Pan’s Labyrinth) and his son, Esteban (Bruno Núñez Arjona), both of whom are unfamiliar with dance culture and are played by the only professional actors in the ensemble. (The majority were street-cast and found at real raves.)

Luis believes his missing daughter is at a desert rave, and so he and Esteban traverse the dusty landscape for a young woman who may not want to be found. When an army of tank-driving soldiers break up the revelry, the pair ask to tag along with another group on their quest for another outdoor party. The journey proves to be long and arduous: there’s a shortage of food, fuel, and workable roads; a news report on the radio reveals that World War 3 has broken out.

Again, Laxe believes the film’s dystopian outlook is sending teenagers to the cinema. “It’s connecting to the fears and dreams of a generation that wants to change their society,” he says. “I should probably stop using the word ‘young’. It makes me sound paternalistic. But like any raver, I know that this society is not sustainable. We just wait for the shift.” Is it better to refer to himself as an outsider, then, perhaps one with a young spirit? “In a way, the archetypal raver is Peter Pan. But I don’t like that some of them are escapist, and don’t want to grow.”

I’m speaking to Laxe in The Londoner Hotel, a few hours before Sirāt screens at BFI IMAX during the London Film Festival. Ever since Cannes, where the film won the Jury Prize (unofficially third place), it’s developed a reputation as an existential thriller to watch big, loud, and knowing as little beforehand as possible. The experience is akin to something like The Sixth Sense: you want to be amongst a gasping crowd when certain plot points unfold.

When I question Laxe if he and his co-writer Santiago Fillol were nervous about “the scene”, he knows exactly what I’m referring to. “It was an idea from Santiago. I had trouble accepting it. I thought it was too extreme. But that’s why it’s good – because it’s taboo. But we’re surrounded by death. Why does it have to be taboo if it’s something that happens in reality?”

“I like free party culture. A dance floor in a club has more ego”

Laxe has premiered films at Cannes since 2010 with You All Are Captains, but none with the international attention of Sirāt. It was around a decade ago that he and Fillol started working on the screenplay. On the page, the director admits, the film’s potential is hard to grasp: French production companies turned down a project that would make the audience “suffer”. (Laxe grins and lets me know they’ve since expressed their regret to him.) Instead, most of the financing came from Spain. One of the producers is Pedro Almodóvar, whom Laxe refers to as “a good colleague”.

Did Laxe and Fillol listen to techno when writing? “No. It’s more me who included music in the script. I developed the images of the film dancing on a dance floor. The images of this tribe crossing the desert, I developed them when dancing. I went to Sufi trance ceremonies.” Laxe lists the places he visited: Morocco, France, Portugal, Italy, and so on. He also namedrops psychotherapists like Stanislav Grof, Claudio Naranjo, and Fritz Perls. “Grof wrote a book called LSD Psychotherapy. In this therapy, you experience death and your rebirth. Sirāt is like LSD psychotherapy.”

The director wishes to make a distinction between raving in a desert and partying at a nightclub or music festival. “I like free party culture. A dance floor in a club has more ego. I don’t like the presence of a DJ. I prefer raves where the DJ is hidden, and you have the abstract transcendence of only the sound system in front of you, and you don’t see people with phones taking selfies. At a free party, it’s not about flirting and seducing someone. And it’s not like Burning Man where people dress up for a weekend. For the people in Sirāt, it’s a way of life.”

What’s less apparent from the marketing is how much of Sirāt doesn’t involve music. While Kangding Ray’s score is practically a supporting character, half the film is really about despairing, dehydrated people driving away from civilisation. It’s fitting, then, that Laxe grew up on slow-burn arthouse cinema. “When I was 15, I was completely lost,” he says. “I didn’t have any spiritual reference. But I found a light in cinema. Watching Tarkovsky and Bresson was my first experience of knowing I have a soul inside. I made Sirāt to connect with people.”

Ultimately, Sirāt is a Venn diagram of Laxe’s interests: Tarkovsky, rave culture, and Islam. While religions are typically associated with classical music, Laxe posits that an electromagnetic vibration can be more transcendent than an instrument made of wood or iron. “You don’t know the source of electronic music. It’s easier to feel the mystery. It could be how the angels sing.”

He continues, “Making art is about looking inside yourself. I like the Quran, and I like techno. I don’t know if there’s a dialogue between Islam and rave culture, but in me, there is. Spirituality is about learning to die with dignity. The question is not ‘why do we die?’ but ‘how do we die?’ It’s healthy that spectators die watching the film. The cinema can be a place for catharsis.”

And will Sirāt encourage more people to go raving? “A dance floor gives you a lot of strength, but also a lot of vulnerability. A rave can also have a toxic dimension. Everything, like this hotel where we’re having this interview, has toxicity. I don’t know if people are more likely to go to a rave or a Sufi temple. I hope they find a balance.”

Sirāt is out in UK cinemas now.