Elliot is a socially isolated teenager who is compelled to stalk and kill his fellow classmates. He observes two children from his window and later looks up their names on Facebook to friend request them. When his requests are denied, he murders one classmate, Jacob, in the school bathroom. Detectives are assigned to the case but struggle as Elliot has covered his tracks. Elliot then messages and murders another classmate, David, in his home, leaving a trail of blood.