Theatre: COMMUNICATING DOORS Gielgud Theatre, London W1

When Julia McKenzie last joined forces with Alan Ayckbourn, it was in Woman in Mind (1986), where she played consummately an unhappy housewife whose retreat into a fantasy world, populated by a family which was an idealised reverse image of her own, led to disaster. That character's plight was, well, if not exactly simple, at least a mite unelaborate compared to the predicament confronting Ruella, the role she assumes in Communicating Doors.

Set throughout in the same opulent suite of the Regal Hotel, the action opens in a vaguely dystopic 2014. Poopay (Adie Allen), an endearingly straightforward dominatrix in leather bondage gear, arrives and discovers that the only thing her elderly client Reece (Laurence Kennedy) wants to take down is her signature - as witness to a document confessing all his business crimes and the fact that he allowed his sinister sidekick Julian (Ken Bones) to murder his two wives.

On the run from the latter, who inconveniently reappears, Poopay gets caught up in a weird time-warp. Emerging from the other side of the poky cupboard between the communicating doors, she finds herself in exactly the same suite and, curiouser and curiouser, face to face with Ruella (Julia McKenzie), Reece's supposedly eliminated second wife. She's no spook, either, but alive and well and living in October 1994. Not for much longer, though, if history runs to form, for this is the very night (the confession has revealed) that the wife will be defenestrated.

With the same door giving Ruella access, in turn, to 1974, and young Reece's wedding night with his first wife Jessica (Sara Markland), the play contrives ("contrives" being the operative word) to be both a peppy time-hop comedy-thriller (replete with cod Hitchcock references and sit- commy jokes) and, more poignantly, a wish-fulfilling fantasy in which the storyline of Poopay's sad life is rewritten, courtesy of these chronological curlings-back by McKenzie's spunky, sensible, positive-thinking Ruella.

The piece is very Ayckbournian and not just in its structural tricksiness. You can tell it's by the author of Woman in Mind from the bias of its sympathies. After all, one course of action open to Ruella would be to confront her husband's younger self with the damning document of his life- to-come (acting as benign witch to his Macbeth) in the hope of effecting some change of heart. Instead, she instinctively appeals to Jessica and, gripping hands across the years, the trio of females eventually become a literal image of women pulling together in the rather crude body-over- balcony scene. Significantly, one of the biggest laughs of the evening comes from Ruella's scathing response to John Arthur's likeably thick security officer when he accuses her of being a pathetic intruder who just wants to relive her honeymoon: "No women in her right mind would want to relive her honeymoon..."

In a performance of great, unassuming skill, Julia McKenzie is not prevented by the hectic pace and plottiness from giving valuable hints of Ruella's emotional hurt and depth, while Adie Allen's marvellous Poopay progresses, in the author's production, from brash caricature to vulnerable girl, making the engineered optimism of the close feel genuinely earned.

nTo 6 January (Booking 0171-494 5065)