Unlike New York where attendances and box-office receipts are published weekly West End

Unlike New York, where attendances and box-office receipts are published weekly, West End figures are a closely guarded secret but, like The Mousetrap, Dead Guilty was certainly working on the premise that what you lose in the week, you make up for at the weekend.Don't be fooled, however, into thinking that the thriller is easy money. An overdesigned version of Christie's Murder Is Easy from the team behind TV's Poirot sailed in to the Duke of York's in 1993 with a cast including Richard Attenborough's daughter Charlotte. If The Mousetrap was good enough for her dad (he was in the first cast) then this, by implication, was good enough for her It was not long for this world. His adaptation of Susan Hill's The Woman in Black is now in its eighth year, while last year's Dead Guilty - reviews for which included such choice phrases as "a perfect anaesthetic" and "an irredeemable dud" - not only ran its initial six-month period but was extended for a further three. Now, they are deeply unfashionable: who can remember the last good one? Sleuth? In 1970, Anthony Shaffer, brother of the more famous Peter, notched up a five-year London run with his fiendishly plotted winner, which managed to satirise the Christie country-house genre while serving up a storyline complicated enough to satisfy the most exacting of audiences.Broadway has given us Ira Levin, with Deathtrap his most successful theatrical outing.

"You really were on the edge of your seat," recalls one audience member. "There was a terrifying moment when someone came crashing through a window. That's what you go for: action that you don't expect to happen, the shock." She wasn't too impressed by the chopping-off of Bill Paterson's leg in the stage version of Stephen King's Misery, "but I'll never forget the moment Sharon Gless was suddenly revealed in the doorway in a shaft of light".Stephen Mallatrat clearly understands that the thriller audience wants a good story. Thrillers were enough of a West End mainstay to inspire one of Tom Stoppard's neatest comedies, The Real Inspector Hound, almost 30 years ago.

Instead, Knott trades in plot twists and builds suspense while working the tried and trusted formula of marriage, money and murder.The play's return is being heralded with a predictable chorus of groans. Very early on, we become privy to the fact that the tennis-playing hero has plans for his wife that don't include the word "love". Hitchcock's film version - shot in a mere 36 days and in 3-D to boot - kept faith with the conventions of the piece by holding on to Knott's structure and not falling into the trap of opening the play out and thereby dissipating the tension.Unlike Christie's pot-boilers with their hidden evidence, Knott's play isn't a whodunnit at all. The budget for the less- than-extravagant stage premiere that summer was 10 times the amount. Its West End success was repeated world-wide, although Pravda dismissed the Moscow incarnation as "a low-level bourgeois gutter play".

Twelve Angry Men, recently exhumed by Harold Pinter, is the work of Reginald Rose, while the man with his finger on the Dial is Frederick Knott.This, his first play, was first produced for TV in 1952, the broadcast and its repeat five days later netting him pounds 141. The title is so familiar, half the world thinks it must have been written by Agatha Christie. In fact, it is one of a select band of plays the fame of whose titles eclipses that of the playwright. Who knows that before being catapulted to TV stardom as Private Godfrey in Dad's Army, Arnold Ridley wrote The Ghost Train, that cast-iron staple of repertory and amateur theatre companies up and down the land (as revived only last season to crowd-packing effect in a smart, programme-balancing move by Lawrence Till, artistic director of the Bolton Octagon). Once upon a time, producers could rely on casting a couple of stars (Richard Todd? Nyree Dawn Porter?), issuing injunctions against the press about divulging the name of the rotter in question, watching audiences try to discover whodunnit, and counting the profits And there were profits to be made. Richard Harris's The Business of Murder began in 1980 at the Strand, moved to the Duchess and wound up with an almost six year run at the Mayfair.Anyone who believed the genre was dead and buried (or confined to The Mousetrap, 43 years and counting) will be surprised to learn that Dial M For Murder is back. Unashamed, crowdpleasing moneyspinners, they appeal to conservative theatregoers and, when they work, nearly everyone's happy.

This, or something very like it, reached its apogee in the hands of such leading thrill merchants as the urbane Francis Matthews and smouldering Gerald Harper, both of whom capitalised on their TV careers as Paul Temple and Adam Adamant respectively. Those unfamiliar with the smartly-dressed style of the classic West End thriller as epitomised by Suddenly at Home, or anything by Francis Durbridge, should think Howard's Way with fewer boats and more blood. This fast vanishing art consists, in most instances, of a snowbound cottage, a comfortable box set complete with fireplace upstage right and a reliable chap in sensible shoes standing in front of a log 'n' flame effect rubbing his hands and saying "brrrr" a lot. For all its shocks, surprises and suspense, it is the safest of genres. It's also the best place to rediscover British Fireside Acting. Chief executive Mark Featherstone-Witty said the school was unlikely to close, but added: "We can't go on with such huge debts round our neck. We would be like a Third World country, always owing more and more money.". Just as Constable's landscapes are nostalgic images of the vanished countryside of his childhood rather than depictions of the increasingly industrialised scene around him, the conventional stage thriller cleaves to the comfort of the past.