Roger Cobb (Steve Martin) is the lawyer for a wealthy millionaire, Edwina Cutwater (Lily Tomlin). Edwina is dying and has arranged for her soul to be transferred into the young Terry Hoskins (Victoria Tennant). Roger is to change her will so that all of her money will go to Terry. During the procedure there is a mishap and the soul gets deposited into Roger’s body. Now he has control of half of his body and Edwina the other half. Roger and Edwina can’t stand each other and are in constant battle for control. They have to find a way to get the voodoo priest, Prahka Lasa (Richard Libertini), to take the soul out of Roger and put it in Terry. The only problem is that Terry isn’t quite so willing anymore.