Music teacher Alexandra Polyakova withdrew into herself after her four-year-old son Danya disappeared without a trace during a walk. Even after three years, Alexandra does not lose hope of finding a child, although his search has long been stopped. One day she recognizes her son in a news story, but her ex-husband Anton, the police and colleagues assure that this is a mistake and there is no chance to find the boy. The only one who believes Alexandra is Major Orlov, the father of her student. He begins his own investigation, which leads him to shocking results...