D/S: M. Night Shyamalan. P: Sam Mercer, Barry Mandel. Cast: Mark Wahlberg, Zooey Deschanel, John Leguizamo, Betty Buckley. UK dist (Blu-ray/DVD): 20th Century Fox.

A film of mesmerising awfulness. Rarely has such a perfect combination of goofball characterisation, goofball dialogue and goofball performances come together in a major Hollywood production. The Happening’s daftness is so sincere, one might almost believe it was a deliberate strategy to baffle and disorientate its hapless audience – an attempt, in effect, to emulate the cognitive dissonance of a Dario Argento film, where irrational behaviours and absurd events collude to create bizarre and troubling new realities. But M. Night Shyamalan is no Argento, and badly lacks the deranged imagination to pull off such a gambit.

Credit where it’s due, the film starts intriguingly enough. Pedestrians in and around Central Park, going about their daily business, suddenly start to exhibit strange behaviour: they stand dead-still, begin mumbling incoherent nonsense, start walking backwards. Then it gets nasty. One by one, they begin to kill themselves: knitting-needles in the neck, shooting, jumping off buildings. Bodies start hitting the pavement like rain.

Steadily, inexorably, the pandemic spreads across the North-East of the US. Panicking citizens clamber aboard trains in an effort to escape the advancing wave of suicides, to no avail. The railway network shuts down, stranding would-be escapees in a small town directly in the path of the Happening. Survivalist instincts take over. Civilization is breaking down: nobody knows why, or how to stop it…

Shyamalan shares Frank Darabont’s uncanny ability to set up a compelling scenario full of exciting possibilities, then destroy its credibility with utterly unbelievable character development and laughable behavioural tics. It has to be seen to be believed. Mark Wahlberg, a fine actor given the right material, is totally out of his depth as a humble schoolteacher thrown into a situation beyond his control. He plays it rather like a brain-damaged child, naively trusting one minute, chucking a tantrum the next. Almost everything his character says or does rings oddly false, as if he’s playing a bad actor playing the part of a schoolteacher.

Professional kook Zooey Deschanel plays Wahlberg’s wife like a zonked-out 12-year-old coquette who’s just been goosed prior to each take. Dissatisfied with the intensity of her natural loopiness, Shyamalan trains baby-spotlights on her eyes, shrinking Zooey’s pupils to pinprick-dimensions and magnifying her cartoonish blue irises to freakish size. Presumably he then instructed his lead actress to behave like a malfunctioning fembot; it’s the only explanation for the performance on-screen. (As for John Leguizamo as Wahlberg’s maths-teacher buddy, words fail me.)

Much of the film is taken up with their not-very-exciting trek across country to evade the mysterious Happening, which seems (SPOILER ALERT!) to be an airborne psychotropic agent. At first the authorities believe it to be the result of a terrorist attack, but – after a 5-minute conversation with a crackpot horticulturalist with “WACKO” written in invisible ink on his forehead – Wahlberg comes to realise that it’s actually a defensive measure by Mother Nature. Trees and grasses have suddenly evolved the ability to exude a powerful chemical from their leaves, which is then transmitted by the wind to act upon their perceived antagonist: humanity. People then start topping themselves, under orders from Shrubbery High Command. Keep Watching The Lawn!

The film lurches from one daft vignette to another, as if daring you to keep watching. Unintentional comedy lurks at every juncture. How about the scene where Wahlberg and Wife, with a brace of dozy teens picked up en route, come upon a barricaded house and proceed to beg the owner for some supplies: by way of reply, we see a long rifle barrel slooooowly extend itself from a boarded-up window, towards the back of an unsuspecting teen’s head…then BOOM! blows his head off, like Marvin the Martian v. Daffy Duck. Chilling.

Of course, Shyamalan can conceive of no way to end the thing properly, so it just stops. The psychotropic assault “crests”, then drops off to nothing. It’s An Act Of Nature: We May Never Know Why It Happened. Just as life is beginning to get back to normal in the States, the film abruptly shifts locale to Paris. Pedestrians walking the tree-lined boulevards suddenly stop and stand, mumbling ze nonsense totale… L’Happening, c’est arrivé encore.

You ‘ave, ‘ow you say, been warned.