When even the star of a movie won’t stand up for it, you know something’s gone wrong. And when Mark Wahlberg ranted about what “a bad movie” The Happening was – “Fucking trees, man. The plants. Fuck it. You can’t blame me for not wanting to try to play a science teacher” – he was only saying what many critics and viewers had already said about the film.

But to dismiss M. Night Shyamalan’s deliberately strange eco-parable as just an evil tree movie is to miss the point; it’s only about plants in the same way Invasion Of The Body Snatchers is about plants. Really, it’s about the difficult relationship between humans and nature, both in the sense of the natural world and in the sense of our own mysterious biology.

The opening scene sets up that conflict in a spectacularly creepy way. In Central Park, people are walking, reading, and generally enjoying the outdoors. But then something happens. Everyone freezes. Then they start to move backwards. Some try to speak, but their speech is confused. And then they commit suicide. Soon, similar incidents are happening in other cities along the East Coast, and while people scrabble for explanations – maybe it’s a terrorist attack? – the experts are baffled. No-one knows what’s happening, only that it is.

The film’s refusal to offer up easy answers is clearly part of Wahlberg’s problem with it. As an action star, he usually gets to face off against a clearly defined threat, but The Happening doesn’t give him that. Instead, Shyamalan chooses to shoot what violence there is from a distance, keeping his victims isolated, even from the viewer. This is a film about internal struggles, not external ones. It’s about paranoia, about not being able to see what’s going on in someone else’s head, or to entirely control what’s going on in your own. You can’t run away from depression, and you can’t escape nature.

Every choice Shyamalan makes in this film is a conscious inversion of genre tropes. It’s not just the detached action sequences and the awkward science teacher hero, it’s the quietly discordant soundtrack, the defiantly un-nurturing female characters, and the way the tension repeatedly ramps up and then fizzles away again without any kind of satisfying resolution. Every choice is designed to wrongfoot the viewer, and it’s both effectively unnerving and kind of invigorating to watch the film reject one cliché after another.

Maybe the most interesting decision Shyamalan makes is to give the job of explaining what’s going on to a hotdog-loving weirdo. The nursery owner played by Frank Collison isn’t even named, but his apparently crackpot theory about plants taking revenge on humans for our treatment of the environment turns out to be correct.

Watched today, in a political climate that prioritises charisma over facts even as the polar ice caps melt, that seems oddly prescient – and utterly chilling.