In late-1950s Germany, teenager Michael Berg falls ill and is helped home by Hanna Schmitz, a much older woman. Following his recovery, Michael seeks out Hanna to thank her, thereby initiating a passionate yet clandestine affair. Their relationship, marked by an unusual ritual where Michael reads to Hanna from various books, bonds them deeply. However, Hanna's inexplicable and sudden decision to leave town brings their intimacy to a halt, leaving Michael heartbroken and bewildered.

Years later, as a law student observing Nazi war crime trials, Michael is shocked to find Hanna as a defendant, accused of heinous crimes during her time as a guard at a concentration camp. This revelation forces Michael to reevaluate their past relationship and the person he thought he knew. The trial's proceedings uncover startling truths and challenge Michael's understanding of justice, love, and atonement, intertwining his personal history with Germany's.