After the goose, gravy, apple sauce and mashed potatoes, the impecunious Cratchit family tuck into a steaming Christmas pudding which is remarkable for everything except its size. "But nobody said or thought it was at all a small pudding," Dickens says. "It would have been flat heresy to do so." Neil Bartlett's inventive, resourceful version of A Christmas Carol at the Lyric, Hammersmith, feels a bit like this diminutive pudding. There isn't actually a tremendous amount on the table but, if you are in a generous Cratchit sort of frame of mind, what Bartlett serves up gives a very adequate impression of a feast.

Bartlett crowds his adaptation with more characters than most. Here you will meet the First Portly Gentleman, A Ghost in Limbo, Scrooge's Sister, Mrs Fezziwig, Scrooge's Ex-Fiancee's Daughter, The Bells of the City of London (St Dunstan's), A Shop Girl, Ignorance, A Second Fat Businessman, Mrs Dilber and A Clerk. This doesn't make it a big-budget show: all the characters in the last sentence are played by Sophie Duval.

The cast of eight do everything from A Small Fire (Angela Clerkin) to Hungry Singing Boy (Phyllida Hancock), except for Richard Briers, who plays only Scrooge. We see Briers first, seated under a large bare light bulb, as if about to be interrogated. Out of the corner of a spectacularly downturned mouth, he growls the inevitable "Bah humbug". It must have been irresistible to cast the man from The Good Life as the man with the bad one. Briers forcibly convinces us that he can squeeze, grasp, scrape, clutch and covet, but his Scrooge doesn't take long to thaw. This is where the show hits an in-built design flaw: we ought to feel pleasure watching Scrooge go gooey, but we want Briers to stay hard and cold and mean. It makes a nice change.

The strength of A Christmas Carol never lay in its tight grasp of the three- act structure or the possibility that it had the suspense potential for a Hitchcock movie. The series of ghosts - let's face it - has a certain inevitability. Wisely, Bart-lett doesn't present a traditional adaptation. He transfers this Dickens, instead, into the idiom of contemporary small- scale theatre. When Scrooge flies out of the window and over the countryside, a square window is lowered over Briers and, in Rae Smith's designs, small snow-covered houses appear around the proscenium arch, providing a sudden aerial perspective. When the front door opens, white petals blow in. When Scrooge moves from his office to his home, he unscrews the light bulb and takes it with him. When the Spirit of Christmas Present (Charlie Folorunsho) ushers in his beneficence it arrives in supermarket trolleys. Taking his cue from Dickens' own readings, Bartlett makes the words the feast. He rearranges them and repeats them: "scratch, scratch" go the pens in Scrooge's office; "chink, chink" go the coins Scrooge drops into the boy's hands on Christmas Day. The show takes the techniques of the fringe - suggestive, mimetic, surreal - and adapts them to a 19th-century venue. The result is a theatrical essay with many inspired flourishes. With them, Bartlett makes Cratchits of us all.

Theatre details: Going Out, page 10.