The seventh book in the series of historical detective stories about Captain Stein and Notary Barbaric
A plague rages in Prague and Emperor Rudolf II. moved to Pilsen with the whole yard. However, a series of crimes threaten the reputation of this virtuous city devoted to the monarch. First, the nephew of the Russian envoy Vlasiev, who had come to negotiate on behalf of Tsar Godunov, mysteriously disappeared. Under the threat of scandal, the town hall instructs the mayor, Leopold Stein, to find the young man. However, the case is more complex and the clues lead to high-ranking figures, so the governor asks his brother, the renowned investigator Joachim Stein, for help.
The captain arrives in Plzeň with Sergeant Jaroš by his side. But terrible news awaits them in the city and a dangerous search is underway, in which the martyred angels are not absent, a secret brotherhood of debauched heretics, two-faced alchemists, murderous spies and a demon, hunting souls in the labyrinth of underground passages under Pilsen.