Frances McDormand plays Doris, Ed's mixed-up wife

Thornton here plays monosyllabic barber Ed Crane, who runs a small salon with his brother-in-law.

Ed is married to the frustrated Doris, played by Frances McDormand, who is having an affair with local furniture tycoon Big Dave Brewster, played by James Gandolfini.

When Ed, needing money to invest in an entrepreneurial scheme called dry cleaning, blackmails his wife's lover into coughing up the cash, it sets in motion a chain of events which spiral rapidly out of control.

Ed's cosy life soon begins crumbling about his ears as he becomes engulfed in murder, mayhem and some seriously weird business involving an apparent UFO.

Throw in a local teenager, played by Scarlett Johanssen, with an ear for music and an eye for Ed, and the usual string of quirky Coen creations, and the scene is set for a pot boiler of mammoth proportions.

Thornton: One of the best actors around

Just as Fargo glorified its long, lingering close-ups of snow-covered landscapes, so The Man Who Wasn't There makes hair-cutting seem like the most fascinating career on earth, with the barber scenes covered in exquisite detail.

But there is far more to this film than mere hair trimmings - the script is as witty and clever as you might expect from a Coen movie, shot through with deliciously dark humour and heart-breaking pathos.

The cast, from McDormand's mixed-up Doris to Tony Shalhoub as a lawyer with some grand ideals, is uniformly excellent.

Ultimately though, this is Thornton's film, and here he doesn't just continue to establish himself as one of the best actors around, he gives one of the finest performances you are likely to see all year.

His largely silent barber - with the majority of his lines heard as voiceover - displays few emotions and is not an easy character to warm to, but Thornton makes him and his peculiar path of guilt and redemption so memorable that Ed is someone who will haunt you long after the closing credits have rolled.

A stunning piece of work, and one of the year's handful of genuine must-sees.

The Man Who Wasn't There is on general release from Friday 26 October.