The central character is Colonel Mikhail Shirokov of the KGB, who learns that his long-time enemy Alexander Stroganov, also known as the Count, has been spotted in the Northern capital. This person is a saboteur who worked for the German special services during the war. With the help of White Guards, the sabotage group "Zigzag," and a mole within the law enforcement agencies, he was planning to carry out a plan to destroy the city. However, Shirokov manages to prevent this from happening.