Blood Rites by S. J. Rozan
Lydia Chin and Bill Smith have been hired by one of the most respected figures in New York City's Chinatown, for what appears to be a simple task - deliver a family heirloom to the young grandson of the recently deceased business colleague of Grandfather Gao. Before they can deliver the heirloom, the grandson is kidnapped and two separate ransom demands are made. While the family of the kidnapped boy tries to freeze them out, Lydia and Bill must quickly learn their way around a city where the rules are different, the stakes are high, and the cost of failure is too dire to imagine. Note: this title is originally published as "Reflecting the Sky" in the US.