Ten-year-old Paul (Harry Eden) lives on an estate with his mother Mel (Molly Parker) and his younger brother Lee (Vinni Hunter). Paul slowly begins to realise that Mel is addicted to heroin. With the help of local waitress Louise (Keira Knightley), Paul tries to rescue his mother from the attentions of local pimp and dealer Lenny (David Wenham), who is all too keen for Mel to continue with her habit.