In 1937, during Stalin's Great Purges, prisoners' letters pleading innocence are routinely burned in Soviet prisons. By chance, one letter survives and reaches Alexander Kornev, a young, idealistic prosecutor. It comes from Stepniak, a loyal party member unjustly imprisoned. Moved by the letter, Kornev tries to reopen the case, but quickly encounters the fear, silence, and rigid bureaucracy of a system built to crush dissent. Determined to seek justice, he travels to Moscow to bring the matter before higher authorities, only to discover that the entire judicial machine is designed not to correct mistakes, but to erase them. His journey becomes a stark confrontation with a totalitarian system where truth is dangerous and innocence offers no protection.