THIS STRANGE, unintentionally disturbing picture looks like the result of a rigorous attempt to test a hitherto persuasive thesis.

Having delivered successive hits with the boring Pursuit of Happyness, the chaotic Hancockand the flawed I Am Legend, Will Smith has established himself as the most bankable (by far) movie star on the planet. With his enviably wide appeal – kids, grannies, Democrats, Republicans, cats and dogs are all on board – Smith could, perhaps, turn any film, however unpalatable, into a fully fledged smash.

How might one check such a hypothesis? Well, you could put him in an endlessly miserable, absurdly unlikely film about a man who travels about the country seeking deserving recipients for his vital organs.

Welcome to Seven Pounds. We'll wake you when it's over.

The film begins with a disarmingly calm Smith phoning the emergency services from the bathroom of a grubby motel room. He announces his own impending suicide and – employing a series of jarring temporal jumps – the film sets out to explain how he ended up in such an unhappy position.

Sometime earlier, Will was, it seems, a tax inspector with an unusual interest in the wellbeing of those he investigated. When he meets Rosario Dawson, an artist with a serious heart ailment, he gets drawn into something a little like a love affair.

But hang on? How can an IRS employee afford such a fancy apartment? What’s with the mysterious newspaper clippings? Why is Will taking such an interest in that poisonous jellyfish? All will be revealed to those with infinite patience.

As you might expect with this cast, the performances are all up to scratch, but this really does look like a film with no potential audience. Gabriele Muccino, director of the marginally less dreary Pursuit of Happyness, invites his cinematographer to jiggle his camera at the grey images, but the arty ambience doesn't mesh with the soapy narrative. Eggheads will find it too sentimental. Popcorn eaters will find it too depressing.

Sure enough, Seven Poundsdied thuddingly at the US box-office. Will Smith is mortal after all.

Directed by Gabriele Muccino. Starring Will Smith, Rosario Dawson, Michael Ealy, Barry Pepper, Woody Harrelson 15A cert, gen release, 123 min *