In a shocking incident that left a school and its local community devastated, a 15-year-old student named William Cornick brutally murdered his Spanish teacher, Ann Maguire, in the middle of a lesson. The case, which was the first of its kind in the UK, sparked a national conversation about the nature of violence in schools and the warning signs that may have been missed. Through interviews with those closest to the victim and the perpetrator, the film explores the events leading up to the murder and the lasting impact it had on all those involved.