 "The Mysterious Affair at Styles" and "The Murder on the Links" are now public domain in the US but will not become public domain in the UK until 2046 (70 years after Christie's death).Christie's grandson, Matthew Prichard, now owns the copyright to his grandmother's works.In 2014, the Christie estate authorised author Sophie Hannah to write a new Poirot book, "The Monogram Murders".