Bernhard Gunther, a 38-year-old Berlin ex-cop turned private investigator, is hired in the summer of 1936 by rich industrialist Hermann Six to recover a diamond necklace stolen from his daughter Grete's house.

The investigation then centers around a certain Von Greis, an aristocrat collecting blackmail material on important personalities for Hermann Göring, which Goering uses for political means.

Gunther then meets Paul's assistant, Marlene Sahm, at the Reich Sports Field during races that are part of the 1936 Olympic games.

It turns out Grete Pfarr, Six's daughter, had killed her husband and his mistress and, with the help of Haupthändler, stole the necklace to generate some cash for an escape, then burned down the house.

Six comes to the terrible realization that Red Dieter holds his daughter and Haupthändler, and he and Gunther retrieve a motor boat to go to the headquarters of the German Strength ring.

Eventually, a top Gestapo officer, Reinhard Heydrich, forces him to agree to go to the Dachau concentration camp to try to covertly befriend Mutschmann, who is a prisoner there, and obtain from him the location of the Von Greis papers.

The major themes of the novel include corruption among the civil servants of the Third Reich, the everyday violence and anti-Semitism of the Nazi regime and the inability or unwillingness of ordinary Germans to act in the face of the coming war.

Although most of the characters are fictitious, the novel's plot also involves historical figures, including Goering, Himmler, Heydrich, Arthur Nebe, and Walther Funk.

However, a historical error is present in Chapter 7, where Kerr refers to a street on the edge the Dahlem section of Berlin as "Clayallee".