Inspired by real criminal cases, a fictional six episode series" German Crime Story: Gefesselt" It tells the story of one of Germany's most notorious serial killer, the so-called "serial killer"; Sour Bucket Killer" In the early 1980s and early 1990s, Raik Doormann kidnapped, tortured, and brutally killed women in his nuclear bunkers, which made the Hamburg region feel scared. Until the victim's consultant and later murder detective Nella Langenbeck discovered clues to his behavior. But at that time, women in the police station were more regarded as secretaries than investigators, so her initial approach gained people's recognition. Despite numerous difficulties, she ultimately found traces of Duman and his terrifying actions.