Real-life story about the long-lasting love between author Iris Murdoch (Judi Dench) and her husband John Bayley (Jim Broadbent) which lasts throughout the years, despite her struggles against Alzheimer's disease. Iris in her younger days (Kate Winslet) is a philosophy professor at Oxford. Iris meets the young Professor Bailey (Hugh Bonneville) and falls madly in love with him. The two form an unlikely pair -- she the brash, outgoing, and vivacious woman, and he a quiet and reserved model of stoic British manhood. Reflecting on their relationship 40 years later, John relates to Iris all of the things he loved and enjoyed doing with her. Recounting with tragic passion, John fights to keep a small silver of Iris' receding mind alive while she fights her struggles against her mind-sapping disease, and to show her the love and kindness that 40 years of a life together with her has meant to him.