The Bremen pensioner Ruth Thalheim (Marie Anne Fliegel) is found dead in her apartment - but nothing indicates a crime. But inspector Inga Lürsen (Sabine Postel) discovers inconsistencies that make her doubt a "natural death". She and Stedefreund (Oliver Mommsen) find out that the dead woman was imprisoned in the GDR as a "political" and was financially supported by the influential Bremen entrepreneur Hans Rodenburg (Jürgen Prochnow). He seems to be involved in the illegal arms trade, and his socialist past leads Stedefreund to the trail of old Stasi cronies. Soon Inga and Stedefreund no longer know which clues to believe - are they being deliberately deceived?