«The Spook Lights Affair» by Marcia Muller,Bill Pronzini

A debutante's missing body, murder most foul, and weird spectral lights in the fog make for a thrilling gaslight-era tale of mystery and detection. In 1895 San Francisco young debutantes don't commit suicide at festive parties, particularly not under the eye of Sabina Carpenter. But Virginia St. Ives evidently did, leaping from a foggy parapet in a shimmer of ghostly light. The seemingly impossible disappearance of her body creates an even more serious problem for the firm of Carpenter and Quincannon, Professional Detective Services. Sabina didn't want to take the case, but her partner John Quincannon insisted it would serve as entree to the city's ultra rich and powerful. That means money, and Quincannon loves the almighty dollar-which is why he is hunting the bandit who robbed the Wells Fargo office of $35,000. Working their separate cases-while Sabina holds John off with one light hand-the detectives give readers a tour of the city the way it was. From the infamous Barbary Coast to the expensive tenderloin gaming houses and brothels frequented by wealthy men, Quincannon follows a danger-laden trail to unmask the murderous perpetrators of the robbery. Meanwhile, Sabina works her wiles on friends and relatives of the vanished debutante until the pieces of her puzzle start falling into place. But it's an oddly disguised gent appearing out of nowhere who provides the final clue to both cases-the shrewd "crackbrain" who believes himself to be Sherlock Holmes.