What's In The Cat, Royal Court Upstairs, London <!-- none onestar twostar fourstar fivestar -->

There's nothing like Christmas for turning the family hearth into a war-zone, but previous efforts to convey this seasonal strife begin to look like festivals of back-slapping cheer once you've witnessed the unrelieved Yuletide ghastliness in Linda Brogan's bleak tragicomedy What's in the Cat.

You may fancy that there's a smack of Mike Leigh about this piece, which arrives at the Royal Court in Paulette Randall's remorselessly unhurried and powerfully acted production. It's 1974, and heavily pregnant, 15-year-old Lauren (Rachel Brogan) returns home, after months of estrangement, for Christmas dinner. It's not just the culinary cock-up (a turkey roasted with a bag of giblets still inside) that gives the occasion a noxiously unpleasant smell.

The girl's parents - Bogey (David Webber), a lazy, self-pitying West Indian, and Margaret (superb Mary Jo Randle), a squiffy, foul-mouthed Irish woman - are stuck in a stifling dependency trap. His suitcase case is packed and he's threatening to return to Jamaica, where he has five bastards. Margaret has a no less chequered past: she left behind a string of children to move in with Bogey. Their union, though, has been a disaster on the race relations front. It's the fact that Lauren was knocked up by a black youth that has left Margaret near-crazed with recrimination. The play's title derives from the proverb "what's in the cat is surely in the kitten". Is history, with inexorable genetic determinism, in the process of repeating itself?

The dialogue - which ranges from the mother's blowtorch blasts ("Sit down, half-breed. They're neither donkey nor horse") to the home-spun poetry of the father's manipulative interventions ("We're all sorry - but sorry don't sorry for we") - sounds both completely convincing and pleasurably heightened.

The production, which captures the family's feral listlessness, is irradiated by Randle's no-holds-barred performance. She presents Margaret as a raging mass of contradictions and drunken disappointment - a woman who finds it easier to express concern for her daughter through apparent contempt and who, while rancid with regret, can roar lewd defiance at her reproving neighbours.

Ironically, given the title, you reckon that it's her behaviour rather than her genes that will shape Lauren's future, pushing the girl back into education at a school with a crèche.

Ends tomorrow (020-7565 5000)