In an apartment building in the new quarter of Rostock found the body of a young woman. All the evidence points to suicide, but the lead investigator, Inspector Albert Shirding, is alarmed by the lack of traces on the bottle of wine in which the cyanide that killed the girl was found. A policeman who lives in the same house begins a thorough investigation, as a result of which he discovers that he, like none of the neighbors, knows almost nothing about each other. Meanwhile, a tangle unraveled by Shirding leads the inspector to the first suspect, who turns out to be his own son, Peter.