Now retired and living in self-imposed exile in the world's most glamorous city, Poirot reluctantly attends a sßnce at a decaying, haunted palazzo. When one of the guests is murdered, the detective is thrust into a sinister world of shadows and secrets.
Harry and her young partner in PI work, Fergus, take on cases from missing persons to murders, but when Fergus's mother turns up, years after abandoning him, they have a deeply personal mystery to solve: Can he trust her?