In 1929, Erich Kästner publishes Emil and the Detectives and becomes wildly successful. He receives a letter from the young Hans-Albrecht Löhr, who asks to meet Kästner. A year later, when the book is adapted into a film, Löhr gets the role of Little Tuesday, and a true friendship blossoms between the writer and the boy. But when the Nazis come to power, Kästner's books are burned and confiscated. Things grow tenser when Hans is recruited into the Wehrmacht, to the disappointment of pacifist Kästner. Kästner and Little Tuesday explore the limits of friendship and loyalty in times of political upheaval.