When architect Newton Davis' girlfriend Becky (Dana Delany) turns down his marriage proposal, his newly-built dream house suddenly becomes nothing more than an empty monument to her rejection. That is, until a chance encounter with Gwen (Goldie Hawn) turns his life upside-down. Intrigued by Newton's story, Gwen visits the house and decides to move in on her own. Resourceful and creative, Gwen is soon fixing up the house and charming Newton's family and neighbors - all the while passing herself off as his new wife! Gwen even befriends Becky, who begins to see a Newton she never knew existed. Horrified at the deception yet unable to stop it, Newton finds himself playing along with her preposterous stories, her attempts at reconciling differences within his family and her campaign for his promotion at work. Finally, he convinces Gwen to fabricate their "divorce" so he can still get married to Becky - until he has a change of heart.