After blowing the whistle on corruption in his precinct, Taipai detective Huang Huo-tu (Tony Leung kai-fai) is "reassigned" to a less prestigious post as Foreign Liason Officer. But when a serial killer--whose trademark is leaving a hallucinogenic black fungus on the brain of his victims--begins cutting a swath through the city, the FBI sends in American agent Kevin Richter (David Morse). Huang is assigned to aid Richter, and as the two work together, they discover that the murders mimic the killings of an ancient, mystic cult and that there could possibly be supernatural forces at work. Taiwanese director Kuo-fu Chen also co-wrote this tense, violent thriller.