The big-screen adaptation of Sloan Wilson's popular novel follows wealthy Ken Jorgenson (Richard Egan) as he brings his wife (Constance Ford) and teenage daughter, Molly (Sandra Dee), to the Maine vacation spot where he worked as a middle-class youth.
When Ken reunites with his former flame, the now-married Sylvia (Dorothy McGuire), it sparks a passionate tryst. Meanwhile, Sylvia's son, Johnny (Troy Donahue), and Molly begin a romance of their own, unaware of their parents' affair.