In Edinburgh, Scotland, three young people, Rayden (Ewan McGregor), Potato (Ewen Bremner) and Sick Boy (Jonny Lee Miller), live a chaotic and rotten life. They take drugs, have promiscuous sex, and do everything from fraud. In the process of squandering their youth, drugs become the root of all evil. Rayden loves and hates drugs, and tries to quit drugs but ends up repeating the same mistakes. After an orgy, the three of them die of a baby born to a girl named Alison (Susan Vidler). From this point on, the nightmare really comes. Potato was imprisoned during a robbery, and Rayden was sent to the hospital for an overdose of drugs and was forced to detoxify. The terrifying hallucinations and the angry fear in his heart forced him to break away from drugs. It seems that the new life is beautiful, but the old friends Begby (Robert Carlyle) and others come to the door and bring him endless troubles again... This film is based on Irvine Welsh's novel of the same name.