When Rosa Wilder (Sarah Spale) takes on her latest case, she has no idea that it will lead her and her partner Manfred Kägi (Marcus Signer) to the edge of their darkest inner abysses. A serial offender seems to be targeting black sheep of the police, whose missteps he punishes with death. Some see in the mysterious avenger a fighter against abuse of authority, others are increasingly worried about the security of the state.