Two shots are fired in a family home in Munich. Batic and Leitmayr find Michaela Danzer dead and her partner Daniel Ruppert unconscious. Quirin, the dead man's six-year-old son, has disappeared along with the murder weapon. During the emergency operation, the doctor discovers a scar from an old gunshot wound on Daniel Ruppert's abdomen, leading Batic and Leitmayr to the trail of an attempted family suicide in Augsburg fifteen years ago. Back then, in an act of sheer desperation, Daniel Ruppert shot his wife and young son. He himself survived, as did his then seven-year-old daughter Ella, whom he couldn't bring himself to shoot. He dismissed her before turning the gun on himself. The fact that the perpetrator from back then is the victim of today is a major headache for Batic and Leitmayr, as is the search for Ella, who is now a young woman and whose trail is lost after numerous therapies. Who shot Ruppert and his new wife that night? And where is Quirin?
