Art of theft

In Thomas’s fun fourth Lady Sherlock mystery (after 2018’s The Hollow of Fear), Charlotte Holmes, who makes her living “as oracle to her fictional brother Sherlock,” agrees to try to save the Maharani of Ajmer from a blackmailer who has hidden compromising letters in the back of a priceless Van Dyck painting destined to be sold at an annual art-sale-cum-masquerade-ball in France. With her partner, Mrs. Watson, and assorted other allies, Charlotte travels to France, where they conduct risky nighttime reconnaissance of the chateau in which the ball will be held and establish false identities that win them invitations. When they learn that the chateau is riddled with peepholes through which compromising pictures might be taken, they realize that the blackmail scheme targets many victims rather than one. Thomas grounds her fanciful premise in solid detective work and does a fine job of evoking the unfulfilled—and seemingly hopeless—romantic longings that afflict several of her sleuths. Fast-paced storytelling and witty prose add further appeal for those who like their historical mysteries playful. Agent: Kristin Nelson, Nelson Literary. (Oct.)