German intelligence will use its agent Mishchenko in Western Belarus. He commands the Neman sabotage group, which is actively collecting data on the place where the Soviet command plans to carry out the next strike. Captain Alekhine is trying to prevent them, under whose leadership there is a special operational team. He is well aware of Mishchenko, but, despite the professionalism of counterintelligence, the agent of the Third Reich is always one step ahead.