Harry and Alex Altman are sent to stay at Camp Spirit Moon. During one of the camp's campfire gatherings, the camp's leader, Uncle Marv, tells a strange ghost story; according to Uncle Marv, a long time ago, a dark fog descended over Camp Spirit Moon, and this fog turned all of the camp's residents into ghosts.
During the campfire session, a girl named Lucy pulls Harry away from the other campers and begins begging him for help. Before she can explain what's wrong, Uncle Marv calls both campers back to the circle.
Much later in the story, Lucy tells Harry that all of the campers except for Harry and his brother are ghosts. Lucy tries to possess Harry against his will, but Harry forces her out of his mind and runs away.
Harry gets his brother, and the boys attempt to run away. The other members of the camp try to stop them. The ghostly campers eventually surround the boys. Lucy is about to possess Harry, but other campers pull her away and try to possess Harry instead. All of the ghosts begin fighting causing them to blend together into a smokey mist. The mist dissipates, allowing Harry and his brother to leave. However, Harry soon discovers that Elvis successfully possessed Alex.
Harry is twelve-years-old, tall, and pretty athletic, with straight black hair, dark brown eyes, and a serious face.
Harry is a cheerful and mellow person, and he likes to have fun. Harry is a little jealous of Alex's beautiful singing voice, but he is good at many sports.