How to make a great whodunnit        

It’s 1950s London and dark deeds are afoot in the West End. There’s been a murder. The would-be director of a film adaptation of Agatha Christie’s The Mousetrap has been bumped off, and cynical Inspector Stoppard (Sam Rockwell) and keen young Constable Stalker (Saoirse Ronan) are assigned to catch the culprit, with half of Theatreland’s movers and shakers suspected.

Directed by feature debutant Tom George, the BAFTA-winning TV director of the BBC’s This Country, See How They Run delivers fast thrills, top-class gags and an ensemble cast of household names and newcomers. Joining Rockwell and Ronan are Adrien Brody, Reece Shearsmith, David Oyelowo, Harris Dickinson, Tim Key, Shirley Henderson, Charlie Cooper, Ruth Wilson and Pearl Chanda.

The film plays as both a straight whodunnit and a meta piece, winking at – and sometimes affectionately mocking – its genre (and showbusiness generally). Given this, we asked Rockwell, Oyelowo (who plays producer Mervyn Cocker-Norris) and Chanda (who plays actor Sheila Sim) what they look for in a good whodunnit. All are keen on the genre, with Rockwell a fan of Murder on the Orient Express, Oyelowo into Knives Out (2019) and Chanda a fan of Clue (1985) and classic Hitchcock thrillers such as Dial M for Murder (1954) and North by Northwest (1959).

Like many of the finest films of its type, See How They Run kicks off with a grisly murder of someone who you may have expected to be a major character. But this trope is quickly subverted with a voiceover by the victim. Chanda explains: “It feels really great that he’s explaining why he died to the audience. That felt really fresh to me, where you have the dead person describing how they died without giving it away.” She adds: “He’s such a creep that you also weirdly root for him.” 

That shocking case won’t solve itself, so you’ll need to call in a consummate professional. Rockwell has his favourites, but they aren’t always the best crime-solvers. “Columbo is the one that is really fun – because he comes in unassuming, tries not to let anybody feel threatened. And then Clouseau is really silly and full of himself. Bit of a jackass.” In See How They Run, Rockwell’s Stoppard is “just a little bit past it. But he is, initially, a good detective and a war veteran. He’s a bit broken as a human being, but he’s a good detective.” 

As for Stoppard’s relationship with the enthusiastic Stalker, Rockwell sees them as “protégé and grumpy teacher. Educating Rita comes to mind. If I was a real detective, I’d probably be somewhere in the middle: a little lazier than Saoirse, but a little more on it than Stoppard.”

To make it really tricky for the coppers on the case, it’s best there’s a plentiful supply of unusual and intriguing people who might just have done the crime, such as Cocker-Norris. Oyelowo explains: “There’s a self-importance to him. There’s a sort of theatrical lovey element that was too delicious to turn away from. I came up in the British theatre early on in my career; there were definitely characters akin to Mervyn Cocker-Norris in my journeying as an actor.” Chanda, meanwhile, thinks there’s something satisfying in British whodunnits where you have a really colourful ensemble cast. “That seems like something which happens often. The Brits do that really well,” she says.

No cinematic tale of mystery worth its salt unravels without a red herring or two. It’s such fun to see the unsuspecting being baffled on screen and even better when a viewer realises they’ve been had too. Chanda says: “Red herrings are just so delicious.” Although it’s not a whodunnit, for these she particularly loves The Sting (1973). “I rewatched it the other day, and there are such brilliant red herrings in that movie, where you’re like, ‘Oh my, why did I not see that? I can’t believe I didn’t see that.’”

By the time the final scenes roll round, with a now-diminished cast left on screen, there has to be a reckoning, with the culprit revealed. Oyelowo says: “I love the moment, and I think this is what everyone loves, when the characters all gather together.” He explains: “When suddenly you find an excuse for them to all be together, and the camera is literally keying in on each of them and it’s ‘Who’s got the best poker face? Who’s actually employing a poker face?’ The solving of the puzzle – when the audience is cast in the role of detective – is the thing we love about whodunnits.”