Yulia Pchelkina and a group of archaeological students arrive in the suburbs of Semiyarsk for excavations. An ancient pagan sanctuary was discovered here, in which human sacrifices were performed a thousand years ago. Nearby, in the middle of a lake shrouded in fog, there is an island where hermits - red-haired witches - have always lived. On the very first day, Yulia overhears a conversation between graduate students and her professor. One night, graduate students saw a woman with loose hair approaching their camp, but they scared her away. Professor Turchaninov demands that graduate students not spread wild rumors among young people. The archaeological camp begins to live its own life with finds and love affairs, until one of the students, the beautiful Zhanna, disappears. And when they find her, they see that the girl’s heart has been cut out... Julia and her new friends, the hunter Kirill Belozersky, nicknamed the Pathfinder, and the old eccentric archivist Feofan Feofanovich Pozolotov, undertake to uncover this monstrous crime.