Hermann Kappes 20th Fall. Germany and Berlin are increasingly dividing into West and East in 1948. The Berlin police are split into several sections. The political and ideological divide also runs through the Kappe family: While the seasoned commissioner Hermann Kappe solves cases in the American sector, his nephew Otto works in the British sector of the city, and Hartmut, Hermann's eldest son, is with the East Berlin police at Alexanderplatz. However, black market trading thrives on both sides. Two smugglers are found dead: Peter Rembowski in Pankow and Max Kallweit in Schöneberg. Dangerous investigations begin in the black market milieu, requiring Hermann Kappe and his communist son to cooperate despite their ideological differences. It happened in Berlin, the grand chain novel about Commissioner Hermann Kappe, reflects fictional criminal cases.