Fifteen year-olds Sharon and Éile are twins. They may look alike but the two girls couldn't be more different. Éile is a quiet and studious girl who does well in school. Sharon, on the other hand, is wild and always in trouble of one kind or another. It's nearly time for the girls to sit their Junior Certificate and time for the troublesome twin to hit the books, but one day she sees something that shakes her to the core. Study is the furthest thing from her mind as she tries to forget her shocking discovery. Meanwhile, Éile is stunned and terrified as she watches Sharon spiral out of control. Can Éile help her twin sister? Or is it too late?