REVIEWED - THE MACHINIST: PLAYED in an astonishing performance by Christian Bale, Trevor Resnik is, to quote an old song title, a man of constant sorrow. His mind is tormented by events in his past. His body is skeletal and wasting away. He suffers from such an extreme form of insomnia that he hasn't slept in a year.

In this condition, Resnik is a danger to himself and his colleagues at the factory where he works. And he is paranoid to the point where the dividing line between reality and hallucination is blurred, perhaps irrevocably.

Clearly, The Machinist is not a movie that would prompt anyone to quote another old song title and declare, "That's entertainment!" However, rewards await audiences adventurous enough to become immersed in Resnik's disturbed and disturbing world. There are even a few glimmers of hope and redemption in his relationships with two women - the prostitute (Jennifer Jason Leigh) who genuinely cares for him, and the single mother (Aitana Sanchez-Gijon) he visits every night at the airport café where she works.

Scott Kosar's intricately crafted screenplay metes out information only as it is needed, intriguing the viewer with clues that may or may not be red herrings: the ominous post-it notes on Resnik's fridge, the Hangman puzzle that is a work in progress, the vintage car that mysteriously keeps on crossing his path, and an amusement park ride, Route 66, which is not at all amusing.

There are echoes of other movies, principally Roman Polanski's Repulsion and The Tenant, and explicit nods to Dostoyevsky's The Idiot (Resnik's bedside reading) in Brad Anderson's assured and compelling treatment of this tangled scenario, which is heavy on brooding atmosphere and tantalising all the way to the end. The Machinist eschews the obvious option of an ambient industrial soundtrack in favour of a full-blown orchestral score, composed by Roque Banos, which is evocative of Bernard Herrmann's most dramatic film music.

The Machinist satisfies as an intriguing thriller on one level, while on another it thoughtfully probes the mental and physical state of its nervy, obsessive and emaciated protagonist steeped in existential angst.

Unrecognisably slimmed down to mere skin and bone, Bale is hypnotic in this role, and the many startling scenes of his bared frame will cause the viewer to reflect on just how far some deeply committed actors will - and should - go for the sake of their craft.