Seventeen-year-old Masha Averina had no idea that she was far from an ordinary girl, but the Chosen One... For more than one millennium, a battle between light and dark forces has been going on on earth for the souls of people. And such a pure and sinless soul as Masha’s only appears once every century. It is not surprising that she is simply doomed to become a guardian angel and save people from demons... But the demons do not sit idly by and dream of getting the Chosen One on their side, because then the girl will become a servant of evil, possessing incredible power. Finding herself at the very epicenter of the battle, Masha is forced to answer the question: who is she really - an angel or a demon?