The Safari Party, Hampstead Theatre, London

A fine feast of prejudices

Esther is in rural Cheshire and she's in seventh heaven – the one pretty amounts to the other to her way of reckoning. With her husband, Lol, who's made it biggish in the world of golf supplies, this upwardly mobile fiftysomething is finding her feet (and losing her heels) in a whole new world of converted barns and bothies.

Just the idea of being able to say "the lager's in the bothy" makes her come over all funny with pleasure. And to socialise with folk who can use the phrase "during lambing" without turning a hair is, for Esther (who is splendidly played by Christine Moore), tantamount to having entered the pages of Pride and Prejudice.

This woman is the farcical reverse-image of those aspiring creatures in Restoration comedy who, having moved from the town, become quiveringly phobic about things rural. Esther, by contrast, is fetishistic about the country. But, as Tim Firth's very funny and enjoyable new play reveals, while she may have acquired the odd local knick knack, a conservatory and an alarm system, she hasn't gained any real knowledge of her surroundings or any genuine new friends.

The eponymous "safari party" – a dinner party where each course is served in a different house – might theoretically have improved matters. The problem is the other participants. The hors d'oeuvres are the responsibility of two indigent (Daniel Crowder and Daniel Cain) whose abusive farmer father died in violent, ambiguous circumstances. Pudding is to be dished up by Inga (Helen Ryan), the antique dealer of Germanic descent whom Lol calls the "Mrs Sodding Bygone Cheshire Expert".

Horses for courses, so to speak. And dark horses, too. The main course is served on the bullet-hole-riddled table where the father met his death. But it's not now in the fraternal farmhouse. It's the pride and joy, in her conservatory, of Esther who bought it from Inga who bought it, in turn, for a tiny amount from the newly bereaved brothers. At each stage in the process its supposed history had become encrusted with fresh, marketable lies. Esther and Lol fondly believe that the holes prove to it to be a Buttyball course – an indoor game played by poor Cheshire farmers of yesteryear who did not "have access" to a golf course.

Firth is an Alan Ayckbourn protégé and at first, you feel that the play is too indebted to the older dramatist's techniques. But Firth is more up to speed than his teacher with the weird mutations in the contemporary world where digital life and derelict tradition can suddenly be superimposed.

A note more reminiscent of Martin McDonagh starts to enter the piece. And as it explores what is good as well as bad in making up stories and false provenances, The Safari Park takes off into an energised madness where the Oresteia seems to have collided with The Antiques Roadshow.

To 19 April (020-7449 4200)