The Spook Lights Affair by Marcia Muller and Bill Pronzini

In 1895, female detectives were not common in San Francisco.  That's one of the things that made the detective agency of Sabina Carpenter and John Quincannon so notable.  The other was the success that they had solving the troubling cases that come to them.  That successful reputation is put on the line when they take on cases that leave their expertise in doubt.

Sabina has been hired as to watch over the debutante of the season, Virginia St. Clair, during her coming out parties.  She should make a stellar marriage, and her affection for a lowly clerk is putting that goal in doubt.  Sabina is to watch over her and make sure Marcus, the clerk, gets nowhere in his pursuit of the heiress.  During her first debutante ball, however, Virginia leaves the dance.  Sabina follows her through the grounds in the dark, only to arrive at the cliffs on which the mansion is situated in time to see her client jump off to her death.  Even more stunning than the girl's suicide is the disappearance of her body.  For while the trail of her fall is clear to see, her body is nowhere to be found.  Sabina is accused of incompetence.

John, in the meantime, has taken on the task of finding the money stolen in a Wells Fargo bank robbery.  The agency will receive ten percent of the money stolen if he recovers it, a handsome reward.  He discovers the gang most likely to have committed the crime, but the case goes nowhere as the robbers are killed off one by one by somebody.  In frustration, John takes on a case where a new oceanside neighborhood is being disturbed by what seems to be a ghost.  Soon the partners find that all three cases are tied together and that to solve any of them, all of them must be solved.

Marcia Muller and Bill Pronzini are recognized stars in the mystery field.  Married for many years, both have been recognized for their mystery series.  Muller created one of the first female detectives, Sharon McCone.  She received the Mystery Writers of America's Grand Master Award in 2005.  Her husband, Pronzini, creator of the Nameless Detective series, received the Grand Master Award in 2008.  Each has a devoted fan following and readers of this combination mystery will be rewarded with the work of two masters at the top of their game.  This book is recommended for mystery readers, especially those who enjoy historical mysteries.