A Nazi officer on trial for war crimes thinks back on his past.

At a session of the International Tribunal of War Crimes, a judge charges Nazi party leader Wilhelm Grimm with crimes against humanity. After Grimm pleads not guilty, the first witness, Father Warecki, is called to the stand. The reverend recalls the spring of 1919, just after the end of World War I: In his small Polish village, the news that Poland is to become a republic is greeted with cheers by the villagers, who eagerly anticipate their independence. When Grimm returns from the war after fighting on the side of Germany, the village graciously welcomes him and offers him his former job as a teacher. War has made Grimm, who lost a leg in battle, an embittered and cynical man who refuses to accept Germany's defeat. Schoolteacher Marja Paeierkowski, Grimm's fiancée, tries to comfort him, but Grimm resents being relegated to a small backwater village and scorns the townspeople as "village idiots." Grimm's diatribe frightens Marja, and three days prior to their wedding, she decides to postpone the ceremony and go to Warsaw. Convinced that Marja deserted him because of his missing leg, Grimm becomes even more resentful when Jan Stys, one of the students, ridicules him as being unfit for a Polish woman. Three months later, Marja, convinced that her love can restore Grimm's humanity, decides to return and marry him. She arrives home just as Jan is being accused of molesting his girl friend, Anna Oremski. Marja goes to speak to the traumatized Anna, who haltingly confides that she was raped by Grimm. That night, Anna drowns herself, spurring an angry crowd to march to Grimm's house and arrest him. Jan, thirsting for revenge, throws a rock at Grimm and puts out his eye. Soon after, Marja leaves for Warsaw, intent on embarking on a new life. Released for lack of evidence, Grimm asks the reverend for a loan so that he can return to Germany, and the clergyman counsels him to renounce his hatred. Back in the courtroom, the next witness is called to the stand--Grimm's brother Karl. Karl remembers 1923 as the year when Germany was in upheaval: Karl, a journalist, and his family are living in Munich when his brother, whom he has not seen for five years, knocks at the door. Karl invites his brother to move in with his family, but becomes disturbed when Grimm acclaims the new doctrines of Adolf Hitler. Grimm gradually rises in the ranks of the Nazi party, which provides him with a glass eye and an artificial leg. After the Nazis begin to foment suspicion and unrest throughout Germany, the Weimar Republic acts to crush the party by arresting its leaders. When the police come looking for Grimm, he hands his nephew Willie his Nazi cross and disappears. Ten years later, the German people awaken, too late, to the tyranny of the Nazis. To escape Nazi oppression, Karl decides to move his family to Vienna. On the eve of their departure, Karl reads that Grimm is to be appointed Deputy Chief Minister of Education at a banquet in his honor. Karl goes to the banquet to tell his brother of his plans and admonishes him to join them, warning that he intends to write an article exposing the truth behind the Reichstag fire once he reaches Vienna. That evening, as the family packs its belongings, a knock is heard at the door and Grimm enters, leading a column of soldiers to arrest his brother. After Karl is sent to a concentration camp, Grimm enrolls Willie in the Hitler Youth. At the trial, the next witness, Marja, takes the stand to testify against Grimm: Marja recalls September 1939, just after Poland's defeat by the Nazis. Having lost her husband in the war, Marja returns to her home town with her daughter Janina, hoping to rebuild their lives. Marja's hope is short-lived, however, for soon the new Nazi commissioner, Grimm, accompanied by Willie, now a Nazi lieutenant, marches into town with his troops. Determined to punish the village, Grimm orders the famished townspeople to produce their quota of food for the German army. One day, Grimm disrupts Marja's class, instructs the children to burn their books and then dismisses them. When Marja learns that Grimm is about to arrest Jan, she warns him to leave town. That night, Jan, who has been wounded in the defense of his country, appears at the parsonnage and, delirious from his injuries, makes an impassioned plea for Polish resistance, then collapses. After secreting Jan in the cellar, Marja and Janina nurse him back to health. Nazi atrocities mount as the village boys are dispatched to labor camps and the girls confined to brothels for the pleasure of the officers. When Grimm orders that horses be stabled in the Jewish synagogue, Marja appeals to his humanity. Ignoring her appeal, Grimm points to Willie and designates him as his spiritual son and symbol of the new order. Later, when Marja discovers that Willie has expressed a romantic interest in Janina, she forbids him to see her daughter. After Grimm orders the Jews herded into cattle cars for deportation to the camps, Rabbi David Levin turns to the reverend for help. As the terrifed victims are driven into the cars, the rabbi exhorts them to resist. The Jews turn to fight, but the Nazis gun them down, and the rabbi intones a prayer of benediction with his dying breath. Later, Willie sneaks into the parsonnage and finds Marja and Janina in the cellar with Jan. Unafraid, Marja challenges Willie's blind obedience to the Nazi party, and moved by her speech, he turns and leaves. Willie begins to sympathize with the villagers and his behavior is reported to Grimm who, as punishment, consigns Janina to the officer's house. Willie begs his uncle to spare Janina, but their conversation is interrupted by the pealing of the church bell, calling the villagers to service. As Grimm forbids the reverend to conduct the service, Marja appears, carrying her dead daughter in her arms for the last rites. After they disappear into the church, Grimm orders Willie not to follow. Denouncing Grimm for betraying his mother and father, Willie strips off his Nazi cross and enters the church. As he kneels to pray, his uncle shoots him in the back. Returning to the present, Grimm refuses to acknowledge the authority of the court, vowing that Germany will rise again. The judge then appeals to the "men and women of the united nations," to render the final judgment of Grimm's guilt.