When a psychic fair arrives in West London, Gemma Doyle, owner of the Sherlock Holmes Bookshop and Emporium, wants nothing to do with it. But somehow, at the urging of Donald Morris, an enthusiastic Sherlockian, she finds herself talked into attending a séance, along with baker and best friend Jayne Wilson, store assistant, Ashleigh, and former pop star Bunny Leigh....