Divorcée Dora Welles, a New York City antiques dealer who's unlucky in love, decides to track down her old high school squeeze, Jim Weybourne, through a detective agency that specializes in locating lost lovers. When Jim turns out to be happily married with two children in California, the resourceful Dora finds a way to insinuate herself casually into their lives. Dora soon begins scheming how to supplant Jim's wife and reclaim him for her own.