Mary Russell and Sherlock Holmes turn the Riviera upside down to crack their most captivating case yet in the New York Times bestselling series that Lee Child called the most sustained feat of imagination in mystery fiction today. Its summertime on the Riviera, and the Jazz Age has come to Frances once-sleepy beaches. From their music-filled terraces, American expatriates gaze along the coastline at the lights of Monte Carlo, where fortunes are won, lost, stolen, and sometimes hidden away. When Mary Russell and Sherlock Holmes arrive, they find their partnership pulled between youthful pleasures and old sins, hot sun and cool jazz, new affections and enduring loyalties. Russell falls into easy friendship with an enthralling American couple, Sara and Gerald Murphy, whose golden life on the Riviera has begun to attract famous writers and artistsand some of the scoundrels linked with Monte Carlos underworld. The Murphy set will go on to inspire everyone from F. Scott Fitzgerald to Pablo Picasso, but in this summer of 1925, their importance for Russell lies in one of their circles recent additions: the Holmeses former housekeeper, Mrs. Hudson, who hasnt been seen since she fled England under a cloud of false murder accusations. When a beautiful young man is found dead in Mrs. Hudsons front room, she becomes the prime suspect in yet another murder. Russell is certain of Mrs. Hudsons innocence; Holmes is not. But the old womans colorful past has been a source of tension between them before, and now the dangerous players who control Monte Carlos gilded casinos may stop at nothing to keep the pair away from what Mrs. Hudsons youthful history could bring to light. The Riviera is a place where treasure can be false, where love can destroy, and where life, as Mary Russell and Sherlock Holmes will discover, can be cheapeven when it is made of solid gold.