It’s tempting to deliver the biggest scoop in theatre criticism: whodunnit in The Mousetrap. But that would spoil the fun, and this production of Agatha Christie’s classic play is all about fun.

The opening is about as hammy as you can get, from the radio play music to the plummy accents, but what develops is a brilliantly distracting detective story.

Jemma Walker holds the piece together as the empathic guesthouse keeper Mollie Ralston, whose guests all have something to hide (sadly Karl Howman disguises his acting skills, with an unchallenging portrayal of the one-dimensional Mr Paravivini).

Steven France lends fine comic pace as the eccentric Christopher Wren, with Bob Saul an energetic policeman and Clare Wilkie an enigmatic Miss Casewell — suitably bitchy to Elizabeth Power’s cranky old Mrs Boyle.

There are plenty of laughs in this play – it’s about as light as murder mystery can be – but character depth shows through after the interval, as the twists come thick and fast.

One of the West End’s longest-runn-ing plays, this is the first UK tour of the show and is definitely worth see-ing, if only to be part of the secret.