East Berlin, 1975: When Oberleutnant Karin Müller is called to investigate a girl's body at the foot of the wall, she realises this is a death like no other. It seems the girl was trying to escape - but from the West. The Stasi want her to discover the identity of the girl but assure Müller the case is otherwise closed. This is not a regime that tolerates a curious mind, and Müller doesn't realise that the trail she's following will lead her dangerously close to home.

Karin Müller, sidelined from the murder squad in Berlin, jumps at the chance to be sent south to Halle-Neustadt, where a pair of infant twins have gone missing. But Müller soon finds her problems have followed her to Halle-Neustadt. She and her team are forbidden by the Stasi from publicising the disappearances, lest they tarnish the town's image. Meanwhile, in the eerily nameless streets and tower blocks, a child snatcher lurks, and the clock is ticking to rescue the twins alive....

Karin Müller of the German Democratic Republic's People's Police is called to a factory in the east of the country. A man has been murdered - bound and trapped as a fire burned nearby, slowly suffocating him. Could his murderer simply be someone with a grudge against the factory's nationalisation, as Müller's Stasi colleagues insist? Why too is her deputy Werner Tilsner behaving so strangely? As more victims surface, it becomes clear that there is a cold-blooded killer out there taking their revenge.

In 1978 East Germany, nothing is at it seems. The state's power is absolute, history is rewritten and the 'truth' is whatever the Stasi say it is. So when a woman's murder is officially labelled 'accidental death', Major Karin Müller of the People's Police is faced with a dilemma. To solve the crime, she must disregard the official version of events. But defying the Stasi means putting her own life - and the lives of her young family - in danger.

Dresden, East Germany, 1980. A man's body is found buried in concrete at a building site in the new town district. When People's Police Homicide Captain Karin Müller arrives at the scene, she discovers that all of the body's identifiable features have been removed - including its fingertips. The deeper Müller digs, the more the Stasi begin to hamper her investigations. She soon realises that this crime is just one part of a clandestine battle between two secret services - the Stasi of East Germany and Britain's MI6.