Autumn 1870. After reading a chapter from the novel “The Past Murderer,” Aleksandra Ilyinichna Tarusova is unexpectedly told that the crime described in it—the murder of a carriage businessman and his lover—actually happened. But when? Before the newspaper was published or after? How does the novel’s author, Andrei Guravitsky, know so many details? Even the investigator found them out not right away. Is the man detained by the police, Ivan Strizhnyev, guilty—or did the real killer, as the novel claims, plant evidence against him? If so, then according to a new science called optography, his image should imprint itself on the victim’s eyes. And Aleksandra Ilyinichna decides to look into them…