Cologne/Bonn Airport: Detective Inspector Mark Kleinert transfers the young Turkish man Baran Sahin, who has been arrested for illegal possession of weapons, to Istanbul. Seemingly a routine operation - until Kleinert receives a call from his lover Carla Paditz, urging him to meet her in Istanbul. When Kleinert arrives at the hotel, Carla is already dead. Mark Kleinert does not realize that Jo Weiß, an undercover BKA officer, is also at the hotel at the same time and is watching him. The fact that there is an even bigger crime behind the murder of the woman on the Bosporus becomes clear after the murder of the imprisoned Baran Sahin. And when Mark Kleinert wants to know why he of all people was responsible for his transfer, his life is already in danger - and not only his.