NO Knowing is the ever-prolific Alan Ayckbourn’s fourth SJT production of the year in Scarborough.

So far, he has delivered one interactive, immersive, semi-improvised play with abundant audience participation, The Karaoke Theatre Company; one revival, Henceforward; and a lunchtime entertainment in two interlinking, bite-sized parts, Consuming Passions, that could be seen separately in the bar or together in the McCarthy.

Now comes the world premiere of No Knowing, a Christmas comedy in two halves that mirrors the brevity of Consuming Passions in the summertime and shares the McCarthy setting. As with Consuming Passions, the intrigue established in the first play is satiated by the revelations in the second, and the structure of each half mirrors the other.

York Press:

He's in the shed again: Jacqueline King's Elspeth and Laura Matthews' Alison have a word about Arthur in No Knowing. Picture: Tony Bartholomew

It all happens in only 75 minutes - plus an interval - in No Knowing where Ayckbourn packs as much into those minutes as many plays don’t into 150.

To add to the joy, company members from the wonderful revival of Henceforward, Bill Champion, Russell Dixon, Jacqueline King and Laura Matthews, now form the Christmas cast, so please make allowance for Champion wearing a somewhat dodgy wig. Such are the timeless perils of the old repertory days.

The central question here is “How well do you really know your partner?”, when Ayckbourn puts Elspeth (King) and Arthur Throkes (Dixon) under the spotlight as they “celebrate 40 years of quiet, safe, unspectacular, ordinary marriage ... or so most of the guests attending their anniversary party are led to believe”.

York Press:

Droning on: Arthur (Russell Dixon) makes his "all-knowing" 40th wedding anniversary speech to son Nigel (Bill Champion), daughter Alison (Laura Matthews) and wife Elspeth (Jacqueline King). Picture: Tony Bartholomew.

Their son and daughter, Nigel (Champion) and Alison (Matthews), know differently as guests gather at the Throkes’ semi-detached suburban family home in August for the 40th birthday party.

In Part One, Knowing Her, Elspeth makes her speech about Arthur, hardly a hymn of praise, with more than a hint of another dissatisfied Ayckbourn woman.

Back Ayckbourn travels to two weeks before Christmas the previous year, where the couple’s sterile conversation over supper exposes their semi-detached relationship, in which he can’t wait to head to his shed and she can’t wait to go out.

Nigel knows why, in the case of the latter, but dour, dreary town-hall drone Arthur keeps his head stuck in the sand.

Come his speech in Knowing Him, he is boasting about how he knows his wife so well, blah blah blah, as he reads from his notes, blithely ignoring her blank expression, sitting at a distance across the room.

York Press:

In the know: Bill Champion's Nigel and Laura Matthews' Alison listen to their mother's speech. Picture: Tony Bartholomew

Cut to a week before last Christmas, another awfully stilted, stupefying supper conversation, with Arthur at his rudest. Enter Alison, desperate to tell her mother of why Arthur is in the shed.

As played so recognisably and humorously by Dixon, Arthur is another of Ayckbourn’s insufferable men, insensitive, set in his ways, self-righteous, stultifying, hypocritical, and oblivious to his own faults, with a dark secret to boot. There will be more than one Arthur at every Christmas party this winter, and as the finale affirms, for all Arthur’s talk of change, he won’t.

Not for the first time in Ayckbourn’s world of failed/frayed/failing, sexless relationships in middle England, King’s Elspeth is the one who engenders empathy for her need for something different, something more. Where Arthur has his secret, she is a dark horse, and hurrah for that.

Written and directed with wicked wit by Ayckbourn, performed with a sting in every turn by his superb quartet, No Knowing will have you wondering what you do and don’t know in the hinterland of secrecy, but I know this: you should see this play...and tell everyone where you’re going.

Alan Ayckbourn’s No Knowing, Stephen Joseph Theatre, Scarborough, until December 24. Box office: 01723 370541 or sjt.uk.com