In September 1915, the young surgeon Aleksey Eiler, returning from the front, visits the mother of his late friend in Moscow—someone he failed to save. Unexpectedly, the woman confesses to murdering her own husband, and soon she dies herself. Eiler is accused of her death, and to clear his name, he begins his own investigation. A journalist from a tabloid joins him. Gradually, it becomes clear that the case is far more complicated than it seemed, and Aleksey faces a difficult choice: hand over the real killer—or go to hard labor himself.