A young policewoman from Hamburg is torn between rigid adherence to her professional ideals and the testosterone-fueled power lust of her head of operations. After her training at the police academy, 24-year-old Laura begins her service in a task force of the Hamburg riot police. Sooner than expected, she realizes that the daily routine in the social hot spots of society is draining. When she makes a serious mistake during an operation, she has to decide what kind of policewoman she really wants to be.

While searching for a serial killer in Berlin's tunnel system, investigator Maik Brunner is hit by a subway train. He wakes up in hospital - in the GDR, in 1984! Lieutenant Kempe is already waiting for him - she is working with him on a series of murders very similar to the one in 2009. Here, too, the perpetrator has poisoned his victims. And here, too, he knows his way around the underground. If Brunner catches the perpetrator in 1984, he could save his girlfriend. In 2009, she is in the hands of the madman...