When the call comes in about a 17-year-old girl murdered after the secret party she held in her parents home, Detective Lottie Parker is first on the scene. As she picks her way through the smashed glasses and the blood spatter on the cream carpet, she is horrified to see Lucys angelic face, silvery-blue eyes forever closed. As Lottie breaks the news to Lucys parents and the partygoers, she discovers that hours before her death Lucy had revealed a terrible secret about her friend Hannah. When Lottie finds Lucys bloodstained clothing hidden in Hannahs bedroom, she has no option but to bring the frightened girl into custody. But Hannah claims to have no memory of the night Lucy died and Lottie begins to question her guilt. Then a 15-year-old boy who also attended the party is pulled from the canal. And as Lottie investigates, she discovers her own son Sean was at the party.