âEmma Corrin â Princess Diana in the latest season of The Crown â has won a coveted role opposite pop idol-turned- actor Harry Styles in her first major film. The pair will play a young couple who become caught up in a polysexual menage a trois. My Policeman, which director Michael Grandage will shoot from April, is set in 1957 and the early 1990s. This is a huge leap for Corrin, 25, who has been nominated for a Golden Globe and a SAG Award for her exquisite portrayal of âShy Diâ in The Crownâs fourth series. In My Policeman she will play Marion, who falls for her best friendâs big brother, Tom Burgess (Styles), a policeman in post-war Brighton. The third member of the love triangle is Patrick Hazelwood, whoâs as besotted with PC Burgess as Marion is. The film, based on Bethan Robertsâs 2012 novel, explores the sexual politics of the 1950s, and the criminalisation of homosexuality. Itâs a period fraught with danger for Patrick and Tom; when itâs safer for the bobby to marry schoolteacher Marion than love Patrick openly. Backed by Amazon Films, it will feature Corrin, Styles and a third actor playing Tom, Marion and Patrick in their youth, and three stars â still to be cast â as the characters 40 years on. In the novel, the story unfolds in the form of two journals: one by Marion, the other by Patrick, offering contrasting views of Tom, from the perspective of the woman, and man, who love him. The project, with a screenplay by Ron Nyswaner (who wrote Philadelphia, starring Tom Hanks and Denzel Washington; and also episodes of Homeland) will doubtless strike a chord with those who have turned C4âs Itâs A Sin, set during the Aids crisis in 1980s London, into a television triumph. My Policemanâs a shrewd pick for Corrin, who is seen as one of our next big actresses. Though rightly garlanded for her performance as Diana (opposite a superb Josh OâConnor as The Prince of Wales) she wonât want to be forever defined by her. Styles, meanwhile, seems to be enjoying switching between screen and concert stage. His first foray into pictures was in WWII epic Dunkirk in 2017. Director Christopher Nolan said he cast the singer because of his âold-fashioned faceâ. His features should fit right into the 1950s setting, too. The budding actor is currently shooting Donât Worry Darlingâ