Furious that her late father only willed her gloomy-looking mansion rather than his millions, Carrigan Crittenden is ready to burn the place to the floor when she finds a map to a treasure. But when she enters the rickety mansion to seek her claim, she's frightened away by a wicked wave of ghosts. Determined to get her hands on this hidden fortune, she hires afterlife therapist Dr. James Harvey to exorcise the ghosts from the home. Harvey and his daughter Kat move in, and so on Kat meets Casper, the ghost of a young boy who is"the friendliest ghost you know." But perhaps maybe not too friendly would be Casper's uncles--Stretch, Fatso and Stinkie--that are determined to drive "fleshies" away.