The Legend of Barney Thomson (15)
Directed by Robert Carlyle
4/5

THE MOST entertaining Thomson in this deeply dark black comedy is not the eponymous Barney but rather Emma Thompson. Memorably funny, she’s unrecognisable in a barmy red wig and ageing make-up as his mother.

Barney Thomson is played by Robert Carlyle who doubles — and rather well too — as director in this, his debut behind the camera.

Thomson’s a charmless Glasgow barber whose own creepy hairdo would be unlikely to make customers feel optimistic and who’s the butt of his fellow haircutters’ sour mockery.

The setting is Glasgow where a serial killer, who posts neatly severed sections of his victims to their families, is on the loose.

The police, led by the resolute cockney detective inspector Holdall (Ray Winstone), are getting nowhere.

It’s Barney’s misfortune that, after a quarrel ending with the accidental death of a colleague, he becomes a murderer himself and ultimately the target of Holdall’s investigation.

Carlyle makes the most of Richard Cowan and Colin McLaren’s acid screenplay, based on the first of Douglas Lindsay’s seven Barney Thomson books, cleverly seguing from simply sinister to cruelly funny as the grisly story progresses.

His use of Glasgow locations roots the increasingly zany events in a visual reality that adds to the story’s ultimate impact.

Thompson’s filthy, foul-mouthed and wickedly funny portrait of Barney’s mother is down to fine acting, not just clever make-up and costume.

Other performances, too, are in tune with the lurid material on offer while the dialogue, peppered with bad language, raises the thought that with the four-letter words deleted, what you’d have is a wise and witty revamp of classic Carry On comedies.

Carry on Killing, perhaps, with a happily hamming Ray Winstone channelling Sid James?