EXCLUSIVE: Here’s an interesting one. Two-time Oscar nominee Felicity Jones (The Theory of Everything), coming off acclaimed drama Train Dreams, will play legendary author Agatha Christie alongside César winner Vincent Cassel (La Haine) in the noir mystery-thriller Eleven Missing Days, which Fortitude International will introduce to buyers at this week’s Cannes market.

Black Swan star Cassel, who will next star in the next installment of The White Lotus, will lead the project as a retired Belgian police detective — in an echo of Christie’s most famous sleuth Hercule Poirot — who is drawn into the mysterious real-life case of the Brit author’s disappearance.

The synopsis reads: “In December 1926, at the height of her fame, Agatha Christie became front-page news when she vanished in bizarre circumstances from her home. In a case of life imitating art, this whodunnit explores the investigation behind her disappearance, strangely resembling an Agatha Christie novel itself where everyone in her life became a suspect.”

Christie’s disappearance made national and international headlines. It captured the public’s attention with leading politicians and fellow writers including Arthur Conan Doyle drawn into the search. Speculation raged over what happened to the author and to this day there remains mystery, with some putting her disappearance down to memory loss as a result of a car crash, and others pointing to the potential of a “fugue” state brought on by trauma or depression.

Bertie Ellwood (Silo) is directing from a screenplay by Ernesto Foronda (Better Luck Tomorrow), based on the book Agatha Christie and the Eleven Missing Days by Christie scholar Jared Cade.

Nicole Elizabeth Berger (He’s Watching You) and Oliver Trevena (The Gorge) will also co-star. More casting is expected to be announced soon.

Currently in pre-production, the picture is on course to shoot this summer in the UK. Range Select is representing U.S. rights.

The film, which has quietly been a decade in the works, is being produced by Serena Films’ Tatiana Kelly (The Catcher Was a Spy), Animus Films’ Jim Young (The Man Who Knew Infinity), Green Light Pictures’ Lucas Jarach (The Dreadful), Nadine de Barros of Fortitude International, Joshua Harris (We Bury the Dead) of Peachtree Media Partners, and James Cunningham of Object & Animal.

Executive producers include Ford Corbett and Nathan Klingher for Gramercy Park Media. Landon Ash, Richie Walls, Brando Eaton, Jeff Rice, Jeff James, Nicole Mejia, Frank Walker and Marc Gabizon also serve as executive producers.

Jones is represented by Independent Talent Group, WME, and Peikoff Mahan. Cassel is represented by Range Media Partners and Agence Adequat. Ellwood is represented by Verve, Range Media Partners and Nord Group.