Synopsis: Emil Jannings stars as Professor Immanuel Rath, the sexually repressed instructor of a boys prep school. After learning of the pupils' infatuation with a local cabaret songstress, he decides to personally investigate the source of such indecency. But as soon as he enters the shadowy Blue Angel nightclub and steals a glimpse of the smoldering Lola Lola (Marlene Dietrich), Rath's self-righteous piety is crushed. He finds himself fatefully seduced by the throaty voice of the vulgar siren, singing "Falling In Love Again." Consumed by desire and tormented by his rigid propriety, Professor Rath allows himself to be dragged down a path of personal degradation.