The film follows the life of a political theorist who becomes deeply involved in the trial of Adolf Eichmann, a high-ranking Nazi officer captured by Israeli agents. The theorist travels to Jerusalem to cover the trial for The New Yorker and finds herself immersed in the harrowing accounts of Holocaust atrocities. As she observes Eichmann, she formulates her groundbreaking theory of the "banality of evil," suggesting that evil acts can stem from ordinary individuals conforming to standard procedures without considering the moral consequences of their actions. This perspective garners significant controversy upon publication.

The theorist's views provoke intense reactions from both colleagues and friends, leading to professional and personal isolation. She faces accusations of being overly sympathetic to Eichmann and blames Jewish leaders for their roles in facilitating Nazi deportations. Amidst the turmoil, the theorist remains steadfast in her convictions, arguing for the importance of independent thought and moral responsibility. Her unwavering resolve highlights the need for intellectual courage in confronting uncomfortable truths, setting the stage for significant shifts in the discourse surrounding justice and morality.