Mystery of the Other Girl

Who is Morna Ross? The phone call interrupted by the piercing scream, the desperate letter written in code, the spooky figure lurking in the shadows, the unexpected kidnapping, and the wild chase where all connected with the girl named Morna Ross. But who is Morna Ross? And what does she want from Stevie (short for Stephanie) Barron? And why would she claim that someone was trying to kill Ian Hend...