Sixteen-year-old Sophie begins an affair with the charming detective who is supposed to solve the murder of her friend Karin. Soon Sophie is also targeted by the killer.

'Sweet 16' is Sophie Reiner - and she's a sly old dog. When her friend Karen is murdered after going to a disco, her perfect world falls apart. She falls in love with the charming detective Mike Kleist and starts a secret affair with him. When another of Sophie's classmates is murdered, the situation in the Reiner family comes to a head. Eventually, Sophie's father is targeted by the investigation. But the killer has already chosen his next victims: they are Sophie and her mother.