Upper Darby’s Tina Fey is shifting from comedy to a darker persona when she appears in a supernatural murder mystery, “A Haunting in Venice,” based on Agatha Christie’s detective story ‘Hallowe’en Party.’

The movie, directed by Kenneth Branagh, who also plays Christie’s famed sleuth Hercule Poirot, will hit theaters Sept. 15, writes Fraki Rudnesky for PhillyVoice.

Fey stars as Ariadne Oliver, a mystery novelist and an old friend of Poirot who has been a recurring character in Christie’s novels.

“(Ariadne Oliver) is much-loved in the Agatha Christie canon,” Branagh told Variety. “She is somebody who gives as good as she gets, and to get that sharpness, mental agility, and cheekiness of Tina was a great quality.”

Fey was Saturday Night Live’s first female head writer, and there are rumors she could succeed producer Lorne Michaels when he retires.

She just wrapped up production on her “Mean Girls” musical movie in the spring.

In “A Haunting in Venice,” Poirot is living in self-imposed exile in post-World War II Venice

He ends up with a murder to solve after reluctantly attending a séance.

The story has supernatural elements, and of course, anyone could be suspect.

Read more about this upcoming murder mystery and Tina Fey’s role in it in the PhillyVoice.

Watch a trailer of the upcoming film, ‘A Haunting in Venice.’