Set in 1938, two years after the events of March Violets, Bernhard (Bernie) Gunther has taken Bruno Stahlecker, another ex-police officer, as his partner.

The two are working on a case where a Frau Lange, owner of a large publishing house, is being blackmailed for the homosexual love letters her son Reinhardt sent to his psychotherapist Dr. Kindermann.

Gunther has no choice but to accept the temporary post of Kriminalkommissar in Heydrich's state Security Service, with a team of policemen working underneath him.

Gunther and his team then follow a number of dead end leads: A Jewish man held on suspicion, Joseph Kahn, is determined to be too improbable a suspect by an expert on psychotherapy, but dies in custody.

However, Arthur Nebe suggests that he had been killed; A violent sexual deviant, Gottfried Bautz, is captured but when an anonymous caller reveals the location of a fifth victim while he is in jail, he must also be let go.

When Gunther interrogates the Ganz parents, they act strangely and eventually reveal they had hired a private detective, Rolf Vogelmann, to help them find their daughter.

There he espies Weisthof, Rahn, and Kindermann, and hears them comment on how they set up the bogus séance to control Himmler for political means, including to excite the population of Berlin against the Jews through propaganda to the effect that they must be responsible for the murders.

In addition, the plot also involves many more philosophical and psychological themes including homosexuality, drug addiction, mental health, psychotherapy, and spiritualism.

Although they are not material to the plot, some important geopolitical events are on the narrator's mind and explicitly referred to in the novel, in particular the Munich Agreement and the Kristallnacht.