When 11-year-old schoolboy Rhys Jones is brutally shot dead, DS Dave Kelly is charged with brining his teenage killer to justice.

When potential witness Claire Olssen is intimidated into changing her statement, the investigation team look for other ways to reinforce their case.

Mercer and his associates are tried for their roles in Rhys's murder, but the verdict fails to bring closure for Mel and Steve as the fractures in their relationship come to a head. Then an unexpected setback leaves Kelly with the toughest decision of his career.