In Nazi-occupied Amsterdam, a Jewish teenage girl named Anne Frank and her family go into hiding to escape persecution. Along with another family, the Van Daans, and a dentist, Mr. Dussel, they take refuge in a secret annex behind her father's business premises. The reality of their situation is grim - they must remain silent during the day to avoid detection, rely on outside help for food and news, and grapple with the constant fear of being discovered. Despite the ever-present danger and the cramped living conditions, Anne's youthful spirit and imaginative mind flourish. She begins to document her experiences, thoughts, and the dynamics within the secret annex in her diary, offering a poignant and insightful perspective on the human condition during such a harrowing time.

As days turn into months, the group's initial solidarity starts to fray under the strain of confinement and the stress of their precarious existence. Personalities clash, resources become increasingly scarce, and the tangible threat outside their hidden door looms larger with each passing day. Yet, in the midst of despair, Anne finds solace in her burgeoning relationship with Peter Van Daan, the teenage son of the other family. Their friendship evolves into a tender first love, providing a glimmer of hope and normalcy against the backdrop of war and the encroaching harshness of reality. Through her writing, Anne captures the essence of their shared human experience, embodying a spirit of resilience and an unwavering belief in the goodness of people despite the surrounding horrors.