Set in the turbulent years surrounding World War II, Season 1 follows Major Nikola Deyanov—codename Sergei—as he leads the fight against fascism in Bulgaria. Haunted by the childhood memory of his father’s murder, Deyanov trains in Moscow before returning home as a Soviet intelligence operative determined to pursue the “enemies of the people.” Opposing him is Bogdan Velinsky, a sharp and calculating officer inspired by the real-life police chief Nikolai Geshev. Their ideological conflict drives the series, portraying two men bound by duty yet divided by belief. With strong performances, high production value, and a tense cat-and-mouse dynamic, the first season explores themes of loyalty, conviction, and the human cost of political struggle.