In Square 45.

An air base for forest protection is located not far from the border. A team of parachute firefighters takes off to extinguish the fire. Newcomer Valentin Volgin shows indecisiveness during his first flight and is late with his jump. Painfully experiencing his first failure, he avoids the gaze of the pretty instructor Irina Aleeva, who witnessed his unsuccessful jump. And then the team receives the task of providing assistance to the border guards, and Valentin, after a tense chase through the burning forest, overtakes and detains the saboteur.