Jean Harlow, a bit player in a Laurel and Hardy film, is spotted by actor Marc Peters, who arranges a screen test for her with director Jonathan Martin. Her first picture for Martin makes her a star, despite criticism of her acting ability from popular actor William Mansfield. Harlow's mother and stepfather take advantage of their daughter's sudden fame and wealth to improve their own standard of living. Wearied by demands from her parents and the studio, Harlow seeks comfort in a marriage to producer Paul Bern, but Bern proves to be sexually impotent and Harlow's well-publicized affairs drive him to suicide. Another marriage fails to assuage Harlow's guilt over Bern's death, and, on the advice of her friend Marie Dressler, she goes East to study acting. News of her mother's illness brings her back to Hollywood, where she is welcomed by producer Louis B. Mayer, who promises to revitalize her career, and Mansfield, who is now in love with her. As her new romance blossoms, Harlow contracts a serious illness and finally dies in Mansfield's arms.