In the Soviet Union of the 1950s, the atmosphere is thick with distrust and repression. Leo Demidov, a state police agent, finds himself trapped in a system that prioritizes loyalty to the party over the truth. When a series of mysterious child murders begins to emerge in a country that denies the existence of crime, Leo faces a crossroads in his life. After being falsely accused of treason and exiled to a remote rural area, Leo joins his wife, Raisa, as he starts to investigate the horrific crimes on his own.
As he delves deeper into the investigation, he discovers that the state frowns upon his quest for justice, and the deaths of the children become a taboo subject. Leo faces pressure from both the government and a serial killer who seems to move in the shadows, unleashing a cat-and-mouse game that leads him to uncover darker secrets about his country. With fear lurking and danger looming, Leo must strike a balance between following his instincts and protecting his wife while risking everything for the truth. This intense odyssey leads him to question not only his loyalty to the regime but also his own humanity in an environment where justice is often buried beneath propaganda. Leo's struggle becomes a chilling reflection of the fight for truth in a grim world.