Mandy, EIGHTEEN, goes to visit her ""pen pal"" Janet for the first time, and anet is a living disappointment -- she giggles, squeals and sulks. Janet's parents, and her handsome cousin, aren't much nicer. Although they are presumably caring for lying grandmother, Mandy comes to suspect that their indifference is criminal neg-igence. And she alerts the police just in time to prevent a kidnapping-murder, her own, and gets back safely to clamber into her parents' bed. Thumb and a blanket, anyone else?