Franziska D. (Julia Koschitz) lives happily together with her partner Sebastian P. (Felix Klare) in Hamburg. As one morning, out of the blue, the police appear at the door and arrest Sebastian for the murder of Constanze Minnich, Franziska is in no doubt that his arrest is a huge misunderstanding. However, after 8 months on remand, during which he repeatedly claims his innocence, Sebastian is sentenced to lifelong imprisonment! The sentence, which is based only on circumstantial evidence, doesn't shake Franziska's belief that her partner is innocent. On the contrary, she is angry that mutual friends have begun to doubt Sebastian's innocence. Franziska's parents also implore their daughter to leave Sebastian: what sort of future could their relationship have? But Franziska remains true to her love and her belief that he is innocent. To prove this, she marries Sebastian in jail.
With time spent in prison, Sebastian changes. Franziska too is now regularly plagued by nightmares—the loudly voiced resistance of family and friends to her marriage begins to take its toll during the night in particular. As friends from his past arrive and tell of an aggressive and completely different Sebastian to the man Franziska knows, her image of him as an understanding and loving man begins to waver.