Jack Wyatt (Will Ferrell), a difficult Hollywood star who tries to have a career comeback by playing Darrin Stephens in a big-screen version of the classic TV series. When Jack sees the beautiful Isabel Bigelow (Nicole Kidman), he thinks that she'd be right for the part of his on-screen wife, Samantha. What he doesn't know is that Isabel really is a witch, which actually makes her a perfect casting choice for the role. Isabel's father Nigel (Michael Caine) is concerned by his daughter's interest in the mortal world, until he's distracted by Iris Smythson (Shirley MacLaine), the movie star who'll be playing Samantha's mother Endora in the film.