IT doesn't happen often, but every once in a while, along comes a film that changes the way you look at similar films forever.

Such a film is Michael Mann's masterful Collateral. Shot on digital video rather than film, it peers further into the night than anything even remotely mainstream has ever done before as the director extracts a pair of career-redefining performances against type from its two leading actors.

As the shades of night constantly move behind him, Tom Cruise is Vincent, a cold-as-ice contract killer who hires a taxi driven by emotionally confident cabbie Max (Jamie Foxx) to ride through Los Angeles as he ticks off a hit list of five names before heading out of the city at dawn. What could be simpler?

Cruise uses all his trademark winning smiles, grand gestures and easy delivery to make Vincent absolutely convincing. Clinical, professional, but not above turning on the charm when needed - in one telling scene he meets Max's mom in hospital and all but charms her to recovery - he feels like the real deal.

Foxx, still best known as a comedian, is forced to rein in his natural exuberance and play Max as a self-knowing observer of daily (or rather, nightly) life. He can spot a person's job by the details of their appearance and he's not above dishing out advice to high fliers - such as Jada Pinkett Smith's stressed lawyer who immediately precedes Vincent as Max's fare.

But the film is at its strongest - and most unexpected - when Vincent and Max are together in the cab. Vincent immediately recognises the chinks in Max's emotional armour and exploits them, almost paternally. He's offering the cabbie a way of accelerating his ambition, of actually acting on his dreams and schemes, rather than using inaction to mask a fear of failure.

Similarly, once Max has got over his (well placed) initial terror at Vincent's monstrous profession, he begins to admire then dismantle the killer's callous cynical logic as he recognises Vincent for the sociopath he is.

Only when the story is forced out of the cab in the final reel does the film stray anywhere close to the conventional - but even then the climax defies expectation, making the viewer question their own expectations and sympathies.

It's a clever trick, and Mann's crowning glory in a film that is painstakingly plotted, meticulously executed and comprehensively involving. It treats death as a product of Vincent's profession without dehumanising the victims and makes us challenge our own perceptions of what he does. Is he, as he puts it, "taking out the trash" or is he ending the life of somebody's parent, partner or sibling?

In dealing with consequences and real emotions Collateral redefines what we can expect from a ride in the back row.

See it at UCI, Odeon