Student Ekaterina Lyubimova, an avid adventurer and seeker of adventures, receives a flattering offer to spend her holidays outside the city in the residence of an oil magnate - a real castle with high towers, carved gates and a tall fence, enclosing this splendor from the eyes of strangers. Having agreed to this adventure, she could not even imagine what it would all lead to: people begin to disappear from the castle, Katerina’s own life is constantly in danger, and those around her blame the awakened spirits of the neighboring castle for everything, seeing a mystical background in the events taking place. After some time, Katya is forced to admit that the criminal lives among them. But who he is can be established by spending the night from Thursday to Friday in the abandoned castle located nearby, from where, judging by ancient legend, once they cross the threshold, they do not return...