Kostenko in Soviet times was a young KGB captain who could have prevented the Chernobyl accident, but failed. For a long time he considered himself guilty and dreamed of going back to the past to change everything. Kostenko was a very honest and decent KGB agent, but the accusation of treason turned him into a dangerous bandit. He dreamed of only one thing — to go back and fix everything. To achieve his goal, he is ready to sacrifice everything, even his life and not just one.