When Allie is contacted by the ghost of a dog, she and Dub investigate the surly new boy at school and his father, who may be running a puppy mill, to see if they are involved.
Mandy and James, exploring Skelton Castle, encounter what appears to be the ghost of Aminta, the faithful deerhound that had guarded the castle's family and grounds.
Retells Washinton Irving's famous yarn about a superstitious school master, rival for the hand of a wealthy farmer's daughter, who has a terrifying encounter with a headless horseman.