Shy graduate student Dmitry Neretin goes to the front to serve as a translator. After several weeks of intense fighting, a lull begins. Battalion scouts advance to the front line and return with a prisoner — a German captain who mysteriously dies at night. Neretin finds out that the captured enemy was killed right in their location. Now Dmitry will have to figure out a traitor among his associates who did not allow the prisoner to betray the secrets of the German army.
September 1939. The beginning of the Second World War. Major Sokolov of Soviet intelligence arrives in Crimea. His main goal is to identify the agent network of the terrorist anti–Soviet organization ROVS. The head of the counterintelligence of the Russian General Military Union is Staff Captain Semenov, alias Krest.