Furious that her late father only willed her his gloomy-looking mansion rather than his millions is ready to burn the place to the floor when she discovers a map to a treasure. However, if she enters the rickety mansion to seek her claim, she's frightened away by a wicked wave of ghosts. Determined to have 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 around in, and so on Kat matches Casper, the ghost of a young boy who's"the friendliest ghost you know." Although maybe not so friendly are Casper's uncles--Stretch, Fatso and Stinkie--who're determined to drive of"fleshies" a way.