At the headquarters, Ritter and Stark are sought out by Vogt, a young and annoying madman who claims he is being followed. Knight throws him out. A little later, the commissioners are called to the corpse of a man. A well-known lawyer was murdered. Vogt also roams around the crime scene in Mauerpark. Ritter and Stark investigate the past of defense attorney Herzog and come across threatening letters from one of his victims, Muller. The detectives interrogate him and get involved in a case that dates back 25 years and has to do with the kidnapping of a baby from an industrial family.