Techno, ecstasy and party, party, party: In the 1990s, Christian, Meike and René were part of the scene and celebrated above the rooftops of Cologne in the legendary "Colonius". It has been around 30 years since the three last saw each other. Now they are brought together by inspectors Ballauf and Schenk after their former friend, the former scene photographer Alex Schmitz, was found murdered in his apartment. He was also a regular at the "Colonius" - has his past caught up with him? A trail on the Internet leads the investigators deep into the old party world and to their former companions. Christian's daughter Svenja also becomes the focus of the investigation. Her mother Gina disappeared without a trace after a night of partying...