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.

"On a foggy summer morning, private investigator Sharon McCone receives a call from her former neighbors, the Curleys. Their usually dependable daughter Chelle hasn't been answering their calls for weeks. Would Sharon check on her? Sharon arranges to visit the building Chelle had been living in and rehabbing in southwest San Francisco. Once it was a nightclub and bar, she learns, and a favorite destination for the city's elite during Prohibition....