On the streets of San Francisco, a cat-and-mouse game can get a little twisted. "Lombard is your Moriarty. Frost. Taking him down will be the most dangerous thing you've ever done." San Francisco homicide detective Frost Easton hadn't seen his estranged friend Denny in years. Not until he dies in Frost's arms uttering a final inexplicable word: Lombard. Denny appears to be the latest victim in a string of murders linked by a distinctive clue: the...