Hans Wolgast is executed with a shot in the head in the idyllic town of Husum to Mozart's Magic Flute. His half-brother, Inspector Anton Glauberg, immediately suspects that the shadows of the family past have caught up with him because Hans was a member of the RAF. Without initially disclosing that he not only knew the dead man but was even related to him, Glauberg begins to investigate, supported by the young, attractive but inexperienced BKA officer Paula Reinhardt. The traces lead to Berlin to the scattered remnants of the RAF and its still functioning cable groups. Wolgast lived there in a shared apartment before he, like so many former terrorists, fled to the GDR in the 1980s. A former roommate of Hans Veith Seewald points out the parallel to Glauberg to a murder case from 1978.