Best friends Perry Gilbert (guest star Chloe Csengery) and Mia Harris (guest star Mina Sundwall) sneak into the woods with Mia’s young sister Zoe (guest star Oona Laurence) in tow. Their search for the mythical Glasgowman leads to a series of violent events, leaving Zoe gravely injured and the other girls missing. While Detectives Rollins (Kelli Giddish) and Carisi (Peter Scanavino) work to locate the suspect, Sgt. Benson (Mariska Hargitay) digs through the stories to distinguish fantasy from reality.