Stella (Kelly Macdonald) is a 15-year-old Scottish runaway working as a prostitute in London. Her pimp, the abusive and manipulative Mr. Peters (James Bolam), controls her life and also runs the local underworld. When one of her friends is beaten by Peters' stooge, Fitz (Andy Serkis), Stella makes an attempt to go straight, with the help of a benevolent drug-addict (Hans Matheson). As she struggles to escape Peters' web, Stella realizes her best course of action is to enact revenge.