For the firm of Carpenter and Quincannon, Professional Detective Services, stopping extortionists is not only grand, but excitingly lucrative.When a pleasant afternoon's bicycling through Golden Gate Park with a friend ends with the revelation of threatening letters, followed by a gunshot in a mansion garden, Sabina Carpenter knows this is a case that demands her immediate and undivided attention.The questions her partner John Quincannon has to unravel are not difficult: Wrixton, a wealthy banker, has met his extortionist's first demand, but the order to pay another $5,000 is too much to face. The banker's real problem is something he doesn't want to reveal. That was fine with the detective, and when he was informed that some private letters were involved and Wrixton absolutely needed them back, there was nothing more Quincannon needed in the way of background. As with so many of San Francisco's elite, the bedroom doors never seemed to stay shut.That was the easy part; far more difficult was the matter of the dead courier, murdered most foully in a locked room within a locked room, creating a trail that will take John Quincannon through most of San Francisco's less savory places and end with a riverboat trip that is anything but a relaxing cruise.
"Sabina Carpenter and John Quinncannon are no stranger to mysteries. In the five years since they opened Carpenter and Quinncannon, Professional Detective Services, they have solved dozens, but one mystery has eluded even them: Sherlock Holmes or, rather, the madman claiming his identity, who keeps showing up with a frustrating (though admittedly useful) knack for solving difficult cases. Roland W. Fairchild, recently arrived from Chicago, claims Holmes is his first cousin, Charles P. Fairchild the Third. Now, with his father dead, Charles stands to inherit an estate of over three million dollars--if Sabina can find him, and if he can be proved sane. Sabina is uncertain of Roland's motives (he will inherit if Charles can't), but agrees to take the case. John, meanwhile, has been hired by the owner of the Golden State brewery to investigate the "accidental" death of the head brew-master, who fell into a vat of his own beer, and drowned. When a second murder occurs, and the murderer escapes from under his nose, John finds himself on the trail not just of the criminals, but of his reputation for catching them. But while John is certain he can catch his quarry, Sabina is less certain she wants to catch hers. Holmes has been frustrating, but useful, even kind. She is quite certain he is mad, and quite uncertain what will happen when he is confronted with the truth. Does every mystery need to be solved?"--
With two con games being run by two deadly villains, Sabina Carpenter and John Quincannon are forced to split up, but when Sabina's life is in danger, John realizes just how much she means to him.
Conducting a dual investigation in the opium dens of San Francisco's Chinatown, Sabina Carpenter and John Quincannon search for missing millionaires against a backdrop of a brewing Tong war.