During the opening moments of Men, a London woman named Harper (Jessie Buckley) watches in shock as a man (Paapa Essiedu) falls past her window to his death, making eye contact with her as he descends in slow motion. We soon learn, in flashbacks, that this man was Harper's emotionally manipulative husband, whom she was preparing to divorce. Was it suicide or an accident? Harper is doomed to ponder this unanswerable question forever. In the meantime, she decides to rent a gorgeous house in the English countryside for a few days, to help her recover from the trauma.

The mood that Men sets early on tells us that this is no wan drama about healing and self-discovery: it is a horror movie. So when the house's goofy owner (Rory Kinnear) shows Harper around the place, making awkward little jokes here and there, our nerves are already on edge. When Harper decides to go for a walk in the forest, we're fearing for her life.

This is all part of the film's design: writer/director Garland has crafted a feminist fable, using horror tropes to make us understand what women go through every day: If Harper can't take a woodsy stroll or have a drink in the local pub without feeling like a target, then no woman can.

Men gets decidedly weirder as it rolls along, as we note that all the male inhabitants of this small English town are played by Rory Kinnear – including a child with the actor's head digitally attached to his wee body. Each represents the various ways men torment women, then pin the blame on the women themselves. (An early scene in which Harper plucks an apple from the tree in front of the house – the homeowner jokes that it's "forbidden fruit" – is an on-the-nose allusion to Eve, the West's original symbol of female blame.) It's a slow burn that builds to a completely over-the-top third act which will either make you gasp or laugh at its gory absurdity, capped off with a shaggy-dog punchline that makes the title of the film seem arch: when "MEN" appears on screen at the end, you can almost imagine Harper uttering the word to herself while shaking her head and rolling her eyes: "Men!"

Garland has crafted a truly distressing chiller, and his narrative has a lot on its mind, even if it leaves us with an array of questions. (Again, this may be Garland's point: whether we believe all this is really happening to Harper, or that she must be imagining at least some of it, pits us on either side of the "Believe all women" debate.) For their parts, Buckley and Kinnear are terrifically committed. But that surreal third act will either keep you in its grip or leave you hopelessly baffled. Love it or hate it, Men is that rare thing: a movie that prompts vigorous post-screening discussion.