17-year-old Charlie Cosser is fatally stabbed by 16-year-old Yura Varybrus at an end-of-term summer party for teenagers. Charlie's dad Martin made his dying son a promise that he would campaign for justice and awareness of knife crime, and his TikTok videos tell the story of a family struggling to come to terms with an act of senseless violence that tore their lives apart.

This episode explores the death of All-American cheerleader Tristyn Bailey, who was killed by 14-year-old Aiden Fucci in 2021.

With unique access, this episode follows the investigation which led to two convictions for 16-year-old Brianna Ghey's murder.