Racing to find a cure to Xie Xue's illness, He Yu and Xie Qingcheng's investigation into the forbidden drug RN-13 grows riskier with each new clue they discover. Along the trail of murdered professors and missing young women they uncover an unconscionable crime, and those responsible for it will stop at nothing to bury the truth. Even worse, the shadowy forces are eager to get their hands on the unique powers of He Yu's blood toxin. And despite his unwillingness to accept his former patient's feelings for him, Xie Qingcheng refuses to let He Yu face this great peril alone.