Mecklenburg, early 1990s: Chief Inspector Groth is sent back to his hometown after years in the West. As an East Germany reconstruction assistant, he is tasked with training his co-workers in West German police work, though he has had his own difficulties with the regulations since the death of his daughter. However, he can still rely on his instincts. When the body of boat rental company owner Siegmar Eck is retrieved from the local lake, Groth knows it was no accident. Why would a good swimmer like Eck drown? And just after visiting Groth and claiming that he was being followed? His colleagues want to shelve the case, but Groth continues to investigate. And in doing so, he comes across a lead that leads him to a waitress in a nearby restaurant and back to an unsolved murder case.