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Chernihiv region more than a hundred years ago and in the twenty-first century. Two girls of the same age: sixteen-year-old Olga, who miraculously finds herself in the family of law graduate Oleksandr, and high school student Alina, who comes on holiday to her aunt in a provincial town. Each belongs to her own time, but mysterious, even mystical events take place in the lives of both of them.
Alexander, who is depressed by the routine work of a notary, finally gets a chance to investigate a crime: a sword from the Napoleonic period has disappeared from an exhibition, but he cannot do without Olga in his search. A small but well-known town is stirred up by a wave of strange deaths, and Alina, joining the search for the killer, realises with horror that it is not quite human...
Dangers and the threat of death do not stop either Olga or Alina.