An empty sailing boat is found on the open sea – Silke Rohwedder's jacket, shoes and handbag on board. No sign of her. Everything looks like suicide. Borowski finds that strange. The impression gets stronger when he examines Silke Rohwedder's apartment. The apartment is sparkling clean, it smells of cleaning supplies. There are a few photos missing from the walls that have obviously been torn down. Did Silke really clean her apartment again before she took the boat out to kill herself? For what reason? And who was in the missing pictures? The neighbors tell Borowski that Silke recently had a boyfriend. But you can't really describe him because you only saw him in passing.
Checking a prescription in Silke's purse reveals another piece of news: Silke was pregnant. Silke's mother confirms that Silke was looking forward to the child. So why the suicide? Mounting evidence leads Borowski to believe it wasn't a suicide. Silke's 19-year-old sister Maxie is behaving very strangely. After learning about her sister's death from Borowski, she goes to a bar and starts a fight, in which she is beaten and hospitalized. What does she know about her sister's death that she doesn't want to tell the police? Does she maybe even have something to do with her sister's death and the beating was something like self-punishment? But Maxie is silent. Even psychologist Frieda Jung can't get any further with her.
Even before Borowski can find out anything useful from Maxie, the young woman escapes from the hospital. Borowski's quest focuses on the phantom of Silke's friend. Silke's mother reports that the man's name is Sandor Kovac and that he supposedly works for the secret service, at least that's what he told Silke. The trail leads to a dead watchmaker of the same name who died of a heart attack in his car some time ago. Obviously, Silke's friend uses the papers stolen from the dead man and uses his identity. But why? Borowski interviews the police officers who were the first to find the dead Kovac. One of them was Claes Möller, who looks amazingly similar to Kovac. His colleagues had already noticed this at the time.
There are increasing suspicions that Möller stole Kovac's papers at the time in order to use the dead man's identity. It turns out that Möller is actually Silke's wanted friend. Did he assume the false identity of being married? Did he murder Silke after she told him about the pregnancy or found out about it? Another family drama unfolds for the police in the Möller house.