It is quite some time since local audiences have been able to indulge the sheer edge-of-the-seat pleasures of a good murder mystery.

`The Business of Murder' sets that straight in spectacular fashion, filling just about all the requirements for an evening that keeps the audience guessing until the final, suitably dramatic denouement.

The play, of course, has to be the thing, with a cleverly ingenious plot. As author Richard Harris is blessed with a fertile imagination or, as one of his characters describes the playwright's profession, "a warped imagination'', it is crammed full with enough devious twists and devices to satisfy even the most blase m `whodunit' fan, with `red herrings' swarming Agatha-like throughout. Harris's characters, however, are far removed from county drawing rooms and rustic cottages. They belong to a far more accessible world that gravitates round flats in North London; add to this the fact that they are given a richly witty and often ironic script and it is easy to see why this play ran for over five years in London's West End, and was hailed as "the thriller of the decade''.

The next item on the list of essential ingredients for that genuine tingle of suspense, is a director who understands the importance of pace and, because this particular play weighs heavily into psychological motivation, the ability to squeeze from his actors, every nuance of gesture that helps lead -- and mislead -- the audience.

Gavin Wilson is just such a director, a professional, whose fine eye for detail is still brilliantly able to keep in view the overall effect. He understands well that, especially in a thriller, unless the audience becomes intrigued with the characters within the first five minutes, he's probably lost them for the night. There is no danger of that with the cast that Mr.

Wilson has assembled for this production.

Thrillers and mysteries are a reviewer's nightmare; describing the plot is obviously not on; even descriptions of the characters are fraught with danger.

Suffice to say that Ken Morgan, one of our best actors who is seen far too rarely these days, has been handed a role that fits him like the proverbial glove -- even though that glove is a frightening mix of velvet and iron. In his portrayal of Mr. Stone, it is his very ordinariness that makes him so sinister: his anxious, fussy politeness as he talks to the police man about the disappearance of his son, is replaced with a tightly tentative smile as he greets the journalist-turned-playwright. The malice builds all right, but so gradually, that it seeps, rather than charges through the audience. John Instone, another fine actor, is the perfect foil for this portrayal of pent-up tension. A strictly down-to-earth London copper who has risen through the ranks, cheerfully agreeing, "I'm an arrogant pig, that's how I get through my day'', Superintendent Hallett is laid-back and understandably cynical about the general human condition. Much of the wit in this play is provided by Hallett and John Instone rises laconically, and perfectly, to the challenge.

Iva Peele, who was praised for her appearance earlier this year in the comedy, `Vanities' for Jabulani Repertory Theatre, plays the role of Dee, the writer who has become the darling of TV mystery thrillers.

She is obviously a gal who can take care of herself. This, in spite of perhaps the weakest link in the play, which finds her in the slightly unlikely position of visiting admirers in strange flats in the first place. Only gradually does she sense that something is wrong with this scenario and, even then, her mounting apprehension is masked by a sentiment also expressed by Stone, that "this sort of thing always happens to other people''.

Gavin Wilson has this trio romping through their confrontation with `fact into fiction and fiction into fact' with the sort of polish not often seen in workshop productions. Come to think of it, we are rapidly reaching the point where productions of any kind are becoming something of a rarity with BMDS.

The excellence of this show makes that inexplicable fact all the sadder.

The cast-list is completed by cameo roles for Sally Mitchell-Williams and Paul Robbins.

Jon Mills' living-room set is strictly functional as befits the sort of London abode you would probably expect a Mr. Stone to inhabit.

All in all, a marvellous evening of escapism, magically delivered by an unusually fine cast. The week's run, incidentally, has been completely sold out.

PATRICIA CALNAN GETTING DOWN TO BUSINESS -- John Instone (left), Ken Morgan and Iva Peele in a scene from `The Business of Murder', now showing at Daylesford.