Looking at the news this past week, you would think the Queen was the only London institution that took up residence in 1952 to entertain tourists with its ritual, scandal and child abuse. But the same is true of Agatha Christie’s The Mousetrap, which has now outlived the Queen to prove the play’s the King.

See How They Run concerns a murder backstage at The Mousetrap‘s 100th performance, a landmark in 1953 that makes a cute joke some 28,400 shows later – as does the contractual ban on movie adaptations being produced during its run, hence this film about the play. Or rather, this film about a murder over a film of a play about a murder based on a murder. Confused? You won’t be. This British comedy is a gentle romp through genre convention and West End nostalgia, whose biggest mystery is why it wasn’t released at Christmas.

Instead of Clue‘s constant barrage of innuendo, See How They Run is a witty affair where the jokes enhance rather than obscure the plot. And though it lacks the sharpness of Knives Out or the background gags of Hot Fuzz, the meta murder mystery is elevated by a killer cast, including Sam Rockwell (being English), Saoirse Ronan (being Irish) and Adrien Brody (being dead) – not to mention Tim Key, Charlie Cooper and Reece Shearsmith, a Who’s Whodunnit of British comedy talent.

The self-aware setup plays like a lighthearted version of Dario Argento’s Opera – and although nobody’s head gets impaled on a coat peg, there is fun to be had in its comical foreshadowing (“He’s a man of his word, he went to Eton!”), deconstructive split-screen and flashbacks, and references to Stoppard and (weirdly) The Shining. It even features Agatha Christie (Shirley Henderson), alongside original Mousetrap cast members Richard Attenborough (Harris Dickinson) and Sheila Sim (Pearl Chanda).

Yet for all its Christie commentary, See How They Run is more respectful of its source than Kenneth Branagh’s pair of Poirot pictures (and moustaches). It balances silliness with reverence, a salute to longevity that will have you laughing in state. If you have no major queues to join this weekend, this is a safe bet for anyone who has seen or intends to see The Mousetrap some time in the next millennium.