An unusual relationship develops between an urban Chinese couple struggling with heroin and a filmmaker chronicling their addiction, in this provocative documentary on drug abuse, filmmaking and friendship. For three years, filmmaker Zhou Hao chronicled the lives of Long and Jun, a couple struggling with heroin addiction in Guangzhou. Zhou captures Chinese junkie subculture, its members languishing in a slum flophouse, the equivalent of a modern day opium den. When Long is hospitalized after a failed robbery, Zhou speaks out from behind the camera to intervene. Still, Long and Jun persist, soon dealing drugs full-time to make ends meet. As the couple increasingly offers lies for answers, Zhou must confront his ethical responsibilities to them, as a friend and a documentarian. USING probes a dark, cruel reality of contemporary Chinese society that has rarely been seen by any audience. Addicts disclose techniques for dealing with police, confronting sham suppliers and staying high throughout the day. Zhou's unflinching depiction of his friends' repeated attempts to quit blurs the line between filmmaker and subject, and raises provocative questions about the ways in which each uses the other.