Carrigan Crittenden (Cathy Moriarty) inherits a shaggy old mansion when her father, a millionaire, passes away. Dissapointed that she only got this mansion, which seems ready to fall apart, she intends to burn it down - until she finds a map that supposedly leads to a hidden treasure in the house. As she enters the mansion to find her treasure, she gets run out by a group of ghosts. She hires afterlife specialist Dr. James Harvey (Bill Pullman) to exercise them. Harveys daughter (Christina Ricci), who he brought with him, soon meets Casper - the friendly ghost of a young boy - who tells her about his uncles, who are not quite so friendly ghosts. A battle for the mansion is ahead...