THEATRE / Idol moments: The Mark - Cockpit, London

Deformities and disfigurements seem to be de rigueur for the heroes in the plays of David Ashton. The central character of The Chinese Wolf, a hit at the Bush in London in 1993, was a hunchback boy who went through a seriously zany Oedipal rite of passage in a south London scrapyard. Now in The Mark, premiered in Daniel Slater's assured production at the Cockpit, the main figure, John (Neil McKinven), is a young Scotsman whose destiny has been distorted and determined by the ugly strawberry birthmark which covers half his face.

Crucially, this blemish has driven him to idolise as a paragon of innocence and perfection his clever, good-looking brother, Tommy (Seamus Gubbins). John wants to accomplish vicariously through him all the feats he himself feels debarred from. But Tommy won't consent to play according to this script, being more interested in sex than in schoolbooks. On the receiving end of worship one minute, idols can all too easily find themselves on the receiving end of a weirdo's deadly weapon the next. Failing to maintain the standards his brother has imposed on him, Tommy is a golden lad who comes to dust somewhat ahead of schedule.

Ashton tells this story backwards in three distinct episodes. We start at the end in a wintry graveyard (the design, by Anabel Temple, excellent) and with a long, mad monologue from the comically obsessive John who has, we gather, served a prison sentence for murdering Tommy in 1960. Still in thrall to his victim, he's just dug up the remains and reburied them in a better spot, and even lies down beside them (his pyjamas at the ready) on the freshly dug grave. The play then shows us two fragments from the past: the mutual recriminations of the parents at Tommy's laying-out, and a scene between the two siblings as Fifties, Everly- brothers impersonations - the one all awkwardness, repression and over-demanding love, the other all casual self- confidence, sexual knowingness and teasing insensitivity to John's hang-ups. It ends with the sight of Tommy posing in exultant, arms-wide nakedness on his way to a swim, the future seemingly all before him, and the sibling who is to shorten that future skulking twistedly in the rear.

The episodes from the past don't, for my taste, sufficiently jar with John's mania- skewed version of events in the initial monologue. But what feels at times like an overly thin, diagrammatic fable keeps getting untidied, happily, by interventions from Ashton's characteristic oddball sense of comedy. There's nothing here, though, to match the exuberant loopiness of The Chinese Wolf, a play in which the hero, washing his hands after a spot of patricide, noticed they were turning black. 'I've just killed my father,' he remarks, giving them an irritated extra rinse. 'My mother's hopped it to Brazil, and now it's trick bloody soap.' By comparison with the Orton-meets-Disney- in-a-jokeshop world he created there, the screwy riffs in The Mark (such as when, for barmily earnest reasons, the reluctant father is persuaded to sing 'Living Doll' a la Cliff Richard over Tommy's coffin) don't have sustained energy, despite some nicely calculated performances from the attractive cast.

Box-office: 071-402 5081