With homicide, it's not strangers you need to worry about. You are most likely to be murdered by someone you know, someone who would never do you harm or so you thought. Someone hiding in plain sight, leading a double life, Someone You Thought You Knew.
Kathy Chou is a typical 19-year-old, living in the Seattle suburb of Renton, Washington. When the bubbly high school senior goes missing, her friends search for her while detectives delve into her past relationships and even her own family history.