Xavier Dolan’s It’s Only the End of the World is one of those angst-ridden dramas focusing on what is commonly referred to as a ‘dysfunctional family’ as if there might be any other kind and it isn’t just a question of degree. This family certainly doesn’t hold back. This family has everyone shouting at everyone else for 95 minutes, blurting out brutal truths that might equally be brutal untruths (hard to tell). It has not been rapturously received. It was jeered at Cannes (even though it won the Grand Prix) and has been described by various critics as ‘insufferable’ and ‘intolerable’, which can only make you think that they haven’t seen an Avengers film for a while. But if it is a failure — if; I haven’t fully decided yet so bear with me — at least it fails promisingly, with spirit, and with a stellar cast turning the volume up to 11, 15… 38!

Some background: Dolan is the French-Canadian wunderkind of art-house cinema. As writer/director he’s helmed six films and won two of the top prizes at Cannes. Also, according to Wikipedia, he is an editor, producer, actor, voice actor, costume designer… and is still only 27. Shaming, I know. (Do you think I could catch up on the costume design, at least? If I start sewing right now? And stay up night after night?) But whereas he’s mostly written his own scripts — Mommy (2014), which won the Jury Prize at Cannes, is outrageously brilliant — this is an adaptation of the 1990 play by Jean-Luc Lagarce, who died of Aids at 38.

Here, our main character, Louis (Gaspard Ulliel, total dreamboat), is 34, gay, a famous playwright, and is returning home after a 12-year absence to tell his family he is dying, although it’s never specified of what exactly. Dolan has assembled the most stellar cast. Nathalie Baye plays Louis’ self-dramatising mother. Léa Seydoux is Suzanne, the younger sister he scarcely knows, who is hungry for his attention. Vincent Cassel is Antoine, the older brother who is all anger and rage, while Marion Cotillard is his wife, Catherine. She does, at least, have some softness about her, but what is she doing with Antoine? Who bullies everyone but her especially. No idea.

We don’t have much idea about much of anything. Time and place are vague. We are only told this happened ‘somewhere, a while ago already’. All I can say with certainty is that from the moment Louis tips up, the volume is turned to 11, then 15, then 37, and possibly 82. ‘Stop screaming!’ Suzanne even screams at one point. Everyone shoots each other down. Apart from Louis, who says little, and instead drifts around as if in some kind of dazed trance. (I felt my own scream coming on and it went: ‘Louis, say what you have to say!’) Catherine, meanwhile, seems to instinctively comprehend why Louis has returned. Why? How? Because …nope, no idea.

It is all intensely claustrophobic. It’s set during a heatwave. The camera is held close to everyone’s face and when it does pan out, it’s to visual metaphors which, I’m forced to concede, are hopelessly trite, like the cuckoo clock in the hall, marking the passage of time, and which will have its own moment. (Alternative title for this film: One Flew Out of the Cuckoo Clock.)

It’s frustrating, I suppose, because we don’t get any sense of what has happened to these people until now, and what has made them as they are. I don’t expect films always to explain themselves, but I do expect the occasional flicker of insight. Yet, all that said, it’s still supremely watchable, as you hang on in there, hoping, hoping, hoping for catharsis, and it’s fun witnessing such a cast going at it hell for leather. I’ve decided it probably is a failure, but that you haven’t heard the last from Dolan. And now I must sew.