On the eve of the war, Lieutenant Ivan Burov, a border guard, returns from a short leave to continue his service on the border between the USSR and Poland. After the German troops attack, Burov is the only one who survives on the section of the state border entrusted to him. Meanwhile, the enemy has already advanced far to the east. Learning that the occupiers are ruling the village where Hanna, Burov's beloved, lives, he decides to wage his own war against the invaders. Alone, amidst swamps and forests, in heat and cold, without sleep or rest, Burov becomes a serious threat to the fascists, a kind of "spirit of vengeance" - for his fallen comrades, for the stolen right to love...