A woman is found stabbed to death in London. A young boy is drawn to the scene to investigate the murder and becomes a suspect himself.

Maintaining tenuous contact only by means of coded messages and cryptic notes with her husband, Sherlock Holmes, and with Holmes' young granddaughter in her safekeeping, Russell will have to call on instincts she didn't know she had as the famous husband and wife sleuths are pursued by a killer immune from the sting of justice.

Days after the encounter at the Swiss waterfall that claimed the lives of Sherlock Holmes and criminal mastermind Professor Moriarty, Pinkerton detective agent Frederick Chase and Scotland Yard Inspector Athelney Jones, a devoted student of Holmes's methods of investigation and deduction, must track down a sinister figure who is determined to stake his claim as Moriarty's successor.

"Mary Russell is used to dark secrets--her own, and those of her famous partner and husband, Sherlock Holmes. Trust is a thing slowly given, but over the course of a decade together, the two have forged an indissoluble bond. And what of the other person to whom Mary Russell has opened her heart: the couple's longtime housekeeper, Mrs. Hudson? Russell's faith and affection are suddenly shattered when a man arrives on the doorstep claiming to be Mrs....

"Mary Russell and Sherlock Holmes untangle the slippery threads of insanity and deadly secrets as they investigate a disappearance in the New York Times bestselling series that Lee Child called "the most sustained feat of imagination in mystery fiction today." A June summer's evening, on the Sussex Downs, in 1925. Mary Russell and Sherlock Holmes are strolling across their orchard when the telephone rings: an old friend's beloved aunt has failed to...

"A queen, a castle, a dark and ageless threat--all await Mary Russell and Sherlock Holmes in this chilling new adventure. The queen is Marie of Roumania: the doubly royal granddaughter to Victoria, Empress of the British Empire, and Alexander II, Tsar of Russia. A famous beauty who was married at seventeen into Roumania's young dynasty, Marie had beguiled the Paris Peace Conference into returning her adopted country's long-lost provinces, single-handedly...