Governments rise and fall. Children grow up to be mothers and then grandmothers. A man steps on the moon. Evolution creates a new version of humankind, the digital native. And serenely The Mousetrap goes on, a resolutely unchanging oasis of certainty in an unpredictable world.

It’s a phenomenon that, if not for the COVID-19 pandemic, would have been running continuously in London for 70 years. As it is, The Mousetrap was made of more durable stuff than the many, many other shows felled by the pandemic. After a break of a bit over a year it was back on stage where it plays an astonishing nine performances a week at St Martin’s Theatre. 

Certainly The Mousetrap’s ability to bounce back was helped by the fact it has one set, a trim cast of eight and isn’t a musical. But still. The Mousetrap has carved for itself a place in theatre history unlikely to be matched.

Its success can be accounted for in two words: Agatha Christie. Only Shakespeare and the Bible have better sales figures and neither Shakespeare nor the Bible have had Christie’s reach via film and television. Who doesn’t love crime fiction? The Mousetrap is a model of the genre – an old-fashioned model, to be sure, but highly satisfying. There is murder, a limited number of suspects, an apparently cosy setting and a thread of darkness that challenges everyone’s equilibrium. At the end, of course, order is restored. 

The production that’s just opened at Sydney’s Theatre Royal (it goes later to Brisbane, Adelaide and Melbourne) is a new one, in so far as any production of The Mousetrap can be called new. There’s no mucking about with it allowed so it comes as standard with realistic 1952 setting (by Isabel Hudson) and slightly stylised performances that are rather wittier than you might expect.

Young couple Mollie and Giles Ralston (Anna O’Byrne and Alex Rathgeber) have turned an old pile of a place, Monkswell Manor, into a guest house. That brings together a highly disparate group of people, types one and all whose only function is to be in the service of Christie’s ingenious puzzle.

It’s winter, the weather socks in and no one can leave. Someone has been done in and the murderer is abroad. Who could it be? Well, that’s for Christie to know and you to find out as everybody dashes in and out of the sitting room in between planting sly clues and being rather enigmatic. 

At a key point in proceedings, dogged Detective Sergeant Trotter (Tom Conroy) seeks information about people’s movements. Was Major Metcalf (Adam Murphy) in the cellar, Mr Paravicini (Gerry Connolly) at the piano, Christopher Wren (Laurence Boxhall) in the kitchen and Miss Casewell (Charlotte Friels) in her room? Or not? And is it relevant? 

Not really, when the enjoyment level is so high and the cast as entertaining as that assembled by director Robyn Nevin. High profile too. Geraldine Turner is the fractious Mrs Boyle spoiling for a fight and Connelly exceptionally funny as Paravicini, who naturally would be suspect no matter what the occasion because he’s a foreign chappie. O’Byrne is luxury casting as the lady of the house, as is Rathgeber as her husband and Conroy as Sergeant Trotter.

The rest are top-notch too. Boxhall is a delight as the fey, unruly haired Wren, named in the hope he will become a celebrated architect but seemingly more at home in the kitchen. Murphy is suitably upright as the Major and Friels a no-nonsense Miss Casewell looking a treat in her ultra-stylish trouser suit. 

What fun.

The Mousetrap runs at the Theatre Royal, Sydney, until October 30. Brisbane, November 4-November 20; Adelaide, December 31-January 15; Melbourne, February 17-March 26.