Based on J. Randy Taraborrelli’s New York Times bestseller of the same name, "The Secret Life of Marilyn Monroe" begins with a portrait of a young Norma Jeane Mortenson as she battles a lonely and loveless existence with an absent mother. Despite the odds, Norma Jeane blossoms into a funny, smart and ambitious woman and soon reinvents herself to become the symbol of an era. She revels in stardom, yet remains a fragile artist, desperate for the approval and protection of men. The outside world never truly sees or understands the real Marilyn, a woman so different from her public persona. As her fame grows, all three of her marriages crumble beneath her quite publicly, including her relationships with Joe DiMaggio (Morgan) and Arthur Miller. Ultimately, Marilyn could never control her inner demons and the onslaught of mental illness inherited from her mother, Gladys (Sarandon) – a woman she loves, hates and wants desperately to save. Although her movie studio told the world that Marilyn's mother was dead, it is the great secret of Marilyn’s life that Gladys remained a vital and troubling part of her world. As Marilyn cares for her mother, her obsession with President John F. Kennedy drives her over the edge and, ultimately, into an insane asylum. Still, as Marilyn Monroe soldiers on, she gives the performance of her life, successfully hiding her darkest secrets from the world.