Beware, this post contains slight spoilers for the film See How They Run. But do not worry, we do not tell you who done it. 

It’s a good time for murder. Well, for murder mystery fans. Whodunits, filled with whimsy and mayhem in extra measure, are experiencing a kind of bloody renaissance—from Glass Onion to Only Murders in the Building. But there’s another film that came out recently that is also a whodunit, except this mystery features a real play that is currently the longest-running play in the world. The first line in the film See How They Run, currently streaming on HBO Max, is: “Agatha Christie’s The Mousetrap, in my opinion, a second-rate murder mystery.”

Fighting words. No wonder there’s a murder at the theatre.

The Mousetrap is a real play by Agatha Christie. The film See How They Run follows detectives played by Sam Rockwell and Saoirse Ronan, as they solve the mystery of who killed a director backstage at The Mousetrap in London. Rockwell filmed See How They Run before going onstage for American Buffalo on Broadway, while Ronan was last seen on Broadway in The Crucible and made her West End debut in 2021 in Macbeth. 

There have been plenty of whodunits released recently (Glass Onion, Confess Fletch, Knives Out, 7 Women and a Murder, Only Murders in the Building). But none of them are set in a theatre, and prominently features a real-life play that is currently running on the West End and will premiere on Broadway in 2023. So naturally, Playbill set out to uncover the best theatre references and in-jokes in See How They Run. How theatre nerdy are the film’s director Tom George and writer Mark Chappell? We’re going to find out.

1. The Title

Eagle-eyed murder mystery fans might have been able to tell that See How They Run is based on an Agatha Christie play just by its title. See How They Run is a phrase from the nursery rhyme “Three Blind Mice,” which was the original title of Christie’s The Mousetrap. And the rhyme is a recurring motif in the play.

2. The Venue

See How They Run is set in 1953, when The Mousetrap was playing at the Ambassadors Theatre. It has since moved to the St. Martin's Theatre, where it is still running today. The first shot of See How They Run is the exterior of the Ambassadors Theatre, with an accurate depiction of The Mousetrap’s neon red marquee. But in the film, the interior of the theatre is much less accurate. The film actually shot its lobby scenes and auditorium scenes at the much-bigger Old Vic.

3. The Players

Because See How They Run features a real-life play, it also features real-life players, who end up being suspects in a murder investigation. Original real-life Mousetrap leads Richard Attenborough (played in the film by Harris Dickinson) and Sheila Sim (Pearl Chanda) have substantive roles in the film—and share an explosive moment at the end featuring a Molotov cocktail. Real-life film producer John Woolf (Reece Shearsmith) is also interrogated by the detectives. And, of course, Agatha Christie (Shirley Henderson) is also a character in a film (and what she does to protect her stage property will have you cackling with glee).

4. The Hamlet References

As the film's murder investigation begins on the set of The Mousetrap (which in the film has a lighter color palette than the real-life set), a playwright played by David Oyelowo asks the detectives if they will, “’Let the galled jade wince.’ Gather all the suspects under one roof and then interrogate each of us in turn until the mystery is solved.” He is quoting a line from Hamlet, while noting the typical structure of a whodunit investigation. Later, Richard Attenborough remarks of The Mousetrap, “I’ll be the first to admit it’s not exactly Hamlet.”

The Mousetrap may not be Hamlet, but it does borrow its title from Shakespeare’s masterpiece. When Christie had to change the title of her play Three Blind Mice because a recent West End play had the same name, she looked to the Bard. In Hamlet, the prince stages a play that he hopes will implicate his uncle in the murder of his father. Hamlet calls that play “The Mousetrap.” You can even call Hamlet Shakespeare’s version of a murder mystery.

5. The In-Jokes

Besides the jokes about the typical tropes of a whodunit, such as one character remarking that “the audience only ever remembers the last 20 minutes,” See How They Run also features plenty of in-jokes that only the nerdiest of theatre fans (or Christie fans) will clock. One example: the film has the actors perform scenes from The Mousetrap, including one scene where the detective walks into the manor from a blizzard holding a pair of skis…except there is no snow on his jacket. Those details are accurate to the production, and the lack of snow has even led to complaints from London's theatre critics.

6. The Contract

In See How They Run, John Woolf is trying to adapt The Mousetrap into a film. Except Christie is not allowing any film adaptations until the play has stopped running, though Woolf is confident the play won’t run for much longer because of the murder.

That is true. Christie did insist on that clause in the show’s contract, even before the play opened on the West End. That real-life detail leads to the biggest industry in-joke of the film: The Mousetrap is still running, even to this day. And a film adaptation was never made. 

In See How They Run, a character dismissively remarks that The Mousetrap doesn’t have longevity because, “It’s a whodunit. You’ve seen one, you’ve seen them all.” That is obviously not true—as The Mousetrap and the new mysteries inspired by Christie’s successful formula can attest, audiences cannot get enough of a murder and to find out who done it.

Have you seen See How They Run? What other theatre references, easter eggs, and in-jokes did you spot?