Review: The Killer Inside Me (18)*****

The consistently watchable Casey Affleck is chillingly plausible as the soft-spoken small-town cop who casually kills whoever gets in his way. On that basis alone The Killer Inside Me is not for the squeamish.

Yet director Michael Winterbottom builds on Thompson's traditional milieu to deliver a slow-burn drama that eventually resembles a Greek tragedy, albeit one transposed to 1950s Texas.

Lou Ford (Affleck) is a handsome, smiling psycho. But his creeping madness is cunningly camouflaged beneath a veneer of respectability.

He is simultaneously giving his attentions to two very different women: one a whore, the other seemingly a clean-living, wholesome lass.

But Lou's ability to corrupt is immense. And when first one, and then the second, girl becomes an obstacle to what he wishes to achieve, his thoughts turn instantly to murder.

An undercurrent of incest and child abuse runs beneath Lou's actions

and gives hints to his mood swings and violent deeds. What's more, Winterbottom allows his camera to linger on Lou's propensity

for brutality, such as when he beats a woman to death. This is nasty, nasty stuff.

There is much to admire in this terrific retro portrait of the US of yore. Winterbottom teases superb performances from Jessica Alba and

Kate Hudson as the hooker and the girlfriend, often against a backdrop of kinky sex as Lou's barely suppressed yearnings flood forth.

But this is a shop window for the brilliant Casey Affleck. As he proved in The Assassination of Jesse James by the Coward Robert Ford, Affleck has an unnatural ability for watchful stillness. He is beyond menacing – an utterly unhinged sadist who believes he can outwit (or kill) one and all.

The picture is also packed with tremendous character support from Ned Beatty, Bill Pullman, Elias Koteas and Simon Baker.

It is horrifying in its simplicity, and horrifyingly effective throughout.

Savage, bleak and on a par with Terrence Malick's Badlands, this is a road trip through the psyche of a maniac. One of the must-see films of the year.