The year is 1989, and Mandy Marsh and her father have just moved to Crowford. John Marsh has a new job at the town's train station, which means that Mandy has to spend most of her summer alone in an unfamiliar town. Until, that is, she makes a strange discovery at the bottom of the garden. Something sinister is lurking in Crowford, something that seems to have ties to the railway line. Mandy makes a new friend who warns her about a ghost that haunts the tunnel, while John is unnerved by claims of a mysterious figure that can sometimes be spotted on one of the platforms at the station. Are these two stories connected? And if they are, does a ghostly warning hint at impending tragedy?