Improbable Fiction, Stephen Joseph Theatre, Scarborough

Any aspiring writer thinking of joining a writers' group may have second thoughts after seeing Improbable Fiction. Alan Ayckbourn's latest play, his 69th, marking the Stephen Joseph Theatre's 50th anniversary, takes its title from a line in that play of reversals and wish fulfilment, Twelfth Night. In Improbable Fiction, simply designed by Roger Glossop and directed by the playwright, Ayckbourn has devised a plot as insanely topsy-turvy as Shakespeare's.

Throughout the first act, we eavesdrop on a meeting of the Pendon Writers' Circle, where six authors are in search of characters, plot, anything, in fact, to overcome writer's block and stimulate inspiration. Despite the encouragement of the genial chairman, Arnold, each has reached an impasse. What could, and occasionally does, seem a long-winded set-up becomes, thanks to Ayckbourn's acutely witty observations, a reminder that life is full of absurdities. The colourful personalities in this circle clash, criticise and encourage, as each describes the progress they haven't made.

The lesbian farmer is bogged down in researching her historical romance; the giggly young journalist is indiscriminately developing her thriller series involving a detective and his hapless sidekick; and the anorakish "sci-fact" scribbler is circling in his own space, oblivious to his malapropisms. The put-upon housewife has the pictures but, alas, no words for her magnum opus, Doblin the Goblin, while the gruff retired teacher is stuck mid-lyric on his latest musical.

As for Arnold, he is resigned to a life of penning instruction manuals. Not even the festive treat of mince pies brings them any good cheer.

The meeting grinds to an end, but not before Arnold has proposed that they pursue the novel idea of joining forces on a collaborative work. Just before the interval, Improbable Fiction changes direction, and fiction springs to life as fact. Throughout the second half, only Arnold remains fixed and independent of the vagaries of situation, period, place, and even planet. Truth could not possibly be stranger than the fictions that unravel at alarming speed in unfathomable directions, as these writers' creative juices flow. With a web of spoof sci-fi characters, a policeman that any crime writer would be proud to disown, a damsel in distress, and the abduction of Arnold's mother by aliens, there's no shortage of storylines to be enjoyed here.

Quite how this uniformly excellent cast, led by John Branwell as the delightfully puzzled Arnold, manages the lightning changes and swift character-swaps is the real mystery. It would be churlish to condemn Improbable Fiction for being what it says it is, especially since Ayckbourn strives to please us every season and, in this case, succeeds, however improbably.

To 17 September (01723 370541)