A Haunting in Venice is an enchanting film full of mystery and intrigue, and Tina Fey's character, Ariadne Oliver, plays a key role. Inspired by author Agatha Christie's novel Hallowe'en Party, the movie introduces viewers to a world of shadows, dark secrets, and murder. Although Christie's novels have been adapted time and time again since the late 1920s, A Haunting in Venice manages to provide a fresh take on the classic sleuth story.
https://screenrant.com/haunting-in-venice-ariadne-oliver-agatha-christie-books-explained/