Set in Philadelphia in 1842, Biddle's second mystery to feature upper-class amateur sleuth Martha Beale (after 2007's The Conjurer
) offers fully human characters and a credible plot. When a wealthy young woman goes missing, Martha and Thomas Kelman, the mayor's assistant in charge of solving crimes, investigate. As their hunt takes them into the homes of the rich, a brothel frequented by the well-to-do and the streets of the poor, Martha and Thomas must face their own feelings for each other and resolve their class differences. Meanwhile, Martha's adopted daughter, Ella, embarks on a search for her real mother, and Martha's young adopted son, Cai, worries about ghosts who come down the chimney. Exceptional attention to period detail helps transport the reader to a past very unlike our own and yet so similar. (Aug.)