While researching a book about legendary mystery writer Agatha Christie, author John Curran cracked a case of his own: Hidden in Christie’s old notebooks were two previously unpublished short stories. Both feature Hercule Poirot, Christie’s mustachioed Belgian detective. Curran will include the stories in his forthcoming Agatha Christie’s Secret Notebooks: Fifty Years of Mysteries in the Making, to be published by HarperCollins this fall. Curran—a Christie “arch-fan,” according to TheBookSeller.com—is one of few people to have access to the notebooks, discovered several years ago at Christie’s vacation home in Devon, England. One of the stories, The Mystery of the Dog’s Ball, was reworked into the novel Dumb Witness. The other, The Capture of Cerberus, was rewritten with the same title and included in the collection The Labors of Hercules.