Vanzarov's Labyrinth

"Vanzarov's Labyrinth" concludes the cycle "Machine of Fear" and the trilogy "Prospero's Labyrinth", "Chimera's Labyrinth", but can be read as a standalone work.
The end of 1898. Petersburg is agitated: the machine of fear has perished, a new invention is needed that goes beyond the boundaries of science. The reason is too important: there is no heir to the throne. Who knows, maybe the new device will be useful to the imperial court. A hunt begins for the machine of truth, during which the inventor's wife dies... Rodion Vanzarov is the only investigator capable of unraveling the intricate mystery, but will he be able to withstand the influence of secret forces and uncover the scheme of dangerous criminals this time?