American pathologist Margaret Campbell has decided to leave Beijing and return home to the US. Her parting duty: assisting the police on a series of murders, which appear to follow the same ritual sacrifice. The Second Opinion The Chinese police have once more been forced to enlist the services of American forensic pathologist Margaret Campbell: this time to investigate a series of four horrific ritual executions that have taken place in Beijing. The Third Degree Detective Li Yan is determined to discover just how one of the victims in particular, an American diplomat, became caught up in the slaying. And he is arguably even more determined to have nothing to do with Campbell. The Fourth sacrifice The polarity that once attracted Yan and Campbell eventually pulls them back into partnership. Yet the closer they are drawn to the truth, the nearer they come to a killer prepared to use extreme force to conceal it.