Marek Krajewski's prose consistently refines the same retro-mystery-novel formula, developed in the previous series with the German detective Eberhard Mock. The action of The Ruler of Numbers, the sixth part of the Edward Popielski series, plays itself out in post-war Wrocław, and mathematics have a major role in the crime intrigue.
The action of the book unwinds around the case of a complicated investigation, which the aged Popielski conducted in 1956 and which ingrained itself so powerfully in his memory that he returned to it in the journals he wrote just before dying. A series of suicides occurred in Wrocław in the sweltering summer of 1956 – fairly suspicious ones, given that the alleged suicides took their own lives in a very peculiar way, and the same way in every case. Count Zaranek-Plater comes to Popielski, who is employed in the legal office mainly to search for angles on the witnesses, with a proposal – the ex-policeman could take on the case of the suicides, as solving it would help the Count in his efforts to gain a considerable inheritance. Popielski takes the case and delves into an investigation which powerfully rattles his rationalist view of the world. Everything points toward the possibility that the crime was committed in the name of a mysterious “god of geometry,” called Belmispar. Sheer nonsense? Not necessarily, for although the god might be fictitious, the corpses are real. This strange affair will not be definitively closed until 2013, by Popielski's son.
The author sets up the suspense differently from his earlier novels, chiefly focusing on the main protagonist and his dilemmas. The case of Belmispar forces the seventy-year-old protagonist to reassess the coherence of his own rationalist world view, and to formulate a clear answer to a seemingly simple, yet fundamental question: What is more important, reason or faith? The plot involving the main protagonist's quandary on this count is one of the novel's most interesting aspects.
We ought also to mention the backdrop of 1950s Wrocław depicted in Krajewski's novel. It is, perhaps, less visual, precise, and suggestive than the image of Breslau from the Mock series, yet it skillfully renders a picture of a city in the Recovered Territories raising itself from the ashes – neither Polish nor foreign, plowed down by the war, with inhabitants that have yet to feel at home.
Translated by Soren Gauger