Bruno Scissere, a heroin addict who has been confined to a psychiatric rehabilitation clinic for several years, has finally been released. He has spent most of his life in similar clinics, always released only to return again. Frightened and unsure of his identity, he prepares to go back into the real world. Outside of the clinic, he observes three different people at a bus stop and begins to perceive himself living their lives for a single day. One of the three people is also a heroin addict, a wretched figure who steals to get his next fix. Another is a young mother who leaves her three-year-old child with a friend so she can have a short holiday, just a day on her own. The third is an entomologist in his laboratory who makes a breakthrough discovery of a rare species of moth.