When the body of a teenager is discovered in a lake, Karin Müller, an officer of the People's Police in East Germany, is called to investigate the case. However, her movements are restricted as she is being watched by the ever-vigilant eye of the Stasi. When the son of one of Müller's team members goes missing, it becomes clear that a terrifying conspiracy is behind the case. Something that soon leads Müller into very deep waters... Will she be able to navigate through this complex political web and find the boy before it's too late?