Sarah Phelps adapting Agatha Christie's The Pale Horse

\'ABC Murders\' writer Sarah Phelps is adapting Agatha Christie novel \'The Pale Horse\' for the BBC.

The screenwriter - who penned the previous BBC Christie dramas \'And Then There Were None\', \'The Witness for the Prosecution\' and \'Ordeal by Innocence\' - wanted to adapt the 1961 book for TV because she wanted to tackle that decade in Christie\'s writing.

Confirming the project to RadioTimes.com, Phelps said: "When I was working on \'And Then There Were None\' [in 2015], there was a little voice in my head saying that I could write a quintet and cover 50 years of the tumultuous blood-soaked 20th century within the genre of the murder mystery.

"Having now done the 1920s, the beginning and end of the 30s, as well as the 1950s, the next one is going to be set in the 1960s."

The plot of the novel centres around historian Mark Easterbrook, who investigates the murder of a Catholic priest found dead in the fog after hearing the confession of a dying woman.

Phelps has faced some criticism for changing some of Christie\'s stories for the adaptations, and sparked much controversy by changing the identity of the killer in \'Ordeal by Innocence\'.

But the screenwriter has defended herself by reasoning she "picks up on clues" she reads in Christie\'s literature and runs with them.

She said: "Agatha Christie plants these little clues in her books and I pick them up and run with them. I\'m honouring the secret, subversive Agatha. There\'s something dangerous about her - and there\'s a lot of academic work to be done on the tension in the novels between the book she knew the public wanted to read and the one she wanted to write. I always think I\'m doing the version of the book she wanted to write."