On February 11th, you will kill a man named Arthur Grimm at the Prater. Voluntarily. And for good reason. Just as young journalist Norah has moved from Berlin to Vienna to finally leave her old life behind, an old beggar woman spits these words at her on the street. Norah is disturbed because it was on the night of February 11th many years ago that something terrible happened. Nevertheless, she dismisses the woman as confused; she must be insane - it can't be any other way - until shortly after, a mysterious man named Arthur Grimm appears in her life. Soon, Norah has a terrible suspicion: does she really have every reason to take revenge on Grimm? What really happened that night, the worst night of her life? And can Norah seek justice without becoming a murderer herself?.