Vacationing on the French Riviera, Mary Russell and Sherlock Holmes befriend Sara and Gerald Murphy, an American couple who attract famous writers and artists—and some of Monte Carlo's underworld thugs. The Murpheys also know the Holmeses' former housekeeper, Mrs. Hudson, who fled England under a cloud of false murder accusations. Hudson soon finds herself under suspicion again, and in this 16th outing (following Island of the Mad), Mary and Sherlock can't even agree whether she is innocent. Meanwhile, some dangerous players are about to further complicate matters.