After completing his three-year service in the Navy, Chase N. Addams returns to his stepmother's home in New York, where he is greeted by his loving girl friend, Kay Burns, and his sister Penny. When Chase learns that Penny has dropped out of high school and has been spending her days in her room playing her piano, he knows that she is still brooding over the death of their father, who passed away when they were children. Lee, Penny's stepmother, is concerned about Penny's odd behavior and discusses her problem with Penny's psychiatrist, Dr. Rossiger. When Rossiger asks Lee about Penny's early childhood in rural Rhode Island, Lee tells him that she married Larry, an investment banker, when Penny was five years old, and that Larry died two years later. Lee then recalls the time just prior to her marriage, when she was traveling by boat from England to America: On board the ship, Lee meets Chris Matthews, a close friend of Larry, and after five days at sea, the two begin a romance. The affair ends, however, when Lee tells Chris that she is sailing to America to marry Larry, the man her mother had earlier forbidden her to wed because he was an alcoholic. After the wedding, Lee spends the next year trying fight Larry's alcoholism and working to win Penny's confidence. One day, Lee, frustrated by her failed attempts to reform her husband, accepts Chris's invitation to a party, which she attends without Larry. At the end of the evening, Chris and Lee stop to inspect a police investigation along the road near a cliff. When Lee learns that the commotion is over her husband, who jumped to his death, she faints in Chris's arms. A photographer quickly snaps their picture, and a local scandal ensues. A larger scandal soon follows, however, when it is discovered that Larry had been stealing money from his investors. Lee refuses to tell Penny the truth about their father's death, and instead tells her that he died of a heart attack. She later moves the family to New York and gets a job in real estate, hoping to make enough money to repay the investors that Larry had fleeced. After Lee concludes her story, Rossiger advises her to take her family back to Rhode Island to live there for the summer. The doctor hopes that the move will cure Penny of her troubling childhood memories, and will help her to transfer her attachment to her father to someone real and alive. Penny reluctantly agrees to go to Rhode Island with Lee and Chase, and they are joined by Chase's friend, Brandon Reynolds. While a romance blossoms between Penny and Brandon, Lee rekindles her romance with Chris. When Penny complains to Chase that their stepmother has been neglecting her family and is only interested in her work, Chase tells Penny the truth about why Lee works so hard. One evening, Lee discovers that Penny has developed an obsessive love for Chris and fled into the night when she saw Lee and Chris embrace. Lee finds her distraught stepdaughter at the same cliffside location where Larry killed himself, and arrives just in time to prevent her from jumping to her death. After Lee tells Penny the complete story about her father's life, Penny returns to school, graduates and resumes her romance with Brandon.