The Second Outbreak gave birth to even more terrible monsters in the Zone than the previous cataclysms. And among them is the Master - the Main Enemy, who possesses a powerful artifact that opens passage to the outside world for the inhabitants of the Zone... Free Walker, former mercenary Andrei Lunev, who recently managed to save all life in the Zone from death, did not yet know that General Ostapenko’s next task will give him the bright opportunity to perish himself or to save all of humanity this time. The Thirteenth Sector discovered in the Zone clearly posed a much greater danger than the other twelve. And now Lunev’s group sought to penetrate the inside-out world of the cursed sector and destroy it from the inside before the Main Enemy managed to open the way for countless monsters and turn the entire planet into one giant Zone...