A young girl from a noble but impoverished family is forced to work as a governess. Ekaterina Nesvitskaya dreamed of going to university, but her plans were boldly violated by the young and cold aristocrat Baron von Berg. An innocent deal between them led to fatal consequences. Now Catherine's lot is the destruction of evil creatures under the guidance of an experienced mentor. They have to learn to trust each other - after all, they are too different. Can a mentor and student overcome mutual distrust and hostility and cope with a mysterious evil?