The crime scenes imply the involvement of supernatural forces. In one case a businessman froze to death in his office in the middle of a heatwave; in another the mistress of a prominent official called the fire department and was later found burned to death - with no sign of a fire ever occurring in her apartment. Richter is skeptical but Huang, who is more receptive to supernatural possibilities, suggests they investigate a local cult. After consulting a scholar in Academia Sinica, Huang and Kevin find that the killings follow a Taoist belief that one must fulfill five forms of suffering required to become a Xian, an immortal being. According to legends, the one who can perform the five rituals is born with double pupils in one eye.