Hiram Stokley is a recently desased corpse who learns that he has 24 hours to mastermind and perform one good deed in order to get into Heaven, so he enlists the help of his long deceased girlfriend Cecily, a ghost, to stop his greedy lawyer, Reginald Ripper and his henchman J. Sinister Hulk from claiming his estate for themselves and protecting his eligible heirs, Chuck, Lili, Hiram's cousin Myrtle, and her son who brings his beach party friends up at the mansion for a pool party while Reginald Ripper also employs his daughter Sinistra, and J. Sinister Hulk's slow-witted associates Chicken Feather and Yolanda to help them terrorize the teens, while dopey biker Eric Von Zipper and his Malibu Rat Pack bikers also get involved in pursuing Yolanda for a share of the estate.

Hiram Stokely is visited in his coffin by Cecily, the ghost of his sweetheart of 30 years ago. She tells him that if he performs a good deed within 24 hours he can gain admittance into Heaven as a member in good standing and also become young again. The good deed is to prevent his scheming attorney, Reginald Ripper, from swindling Hiram's rightful heir, young Chuck Phillips, out of his inheritance. As Chuck, his fiancée, Lili Morton, and his spinster aunt Myrtle Forbush prepare for the reading of the will, Myrtle's swinging nephew Bobby arrives at the Stokely mansion to spend the weekend. Also on hand are Eric Von Zipper and his Rat Pack. Amidst all the mayhem, the villainous Ripper finds it difficult to carry out his plan for doing away with Chuck. When Ripper makes a last attempt at murder in the mansion's basement chamber of horrors, Hiram and Cecily foil the scheme, and the inheritance rightfully goes to Chuck. Having done his good deed, Hiram is given his reward, but it is more than he had bargained for; as Cecily leads him toward Heaven, he becomes 3 years old again.