What could be worse than a vacation in the countryside, without the Internet, mobile communications and friends? When it was Halloween, which fourth-grader Arina was going to celebrate with her friends. But the parents decided to send the girl and her five-year-old sister to their grandmother so that the children could breathe fresh, country air. “Melancholy and hopelessness” - this is what the girl thought on the way to the village. But on October 31, Arina gets acquainted with a completely different holiday, more ancient and dangerous, when spirits walk along the street and characters from Russian folk tales come to life. And it is not recommended at all to go outside the threshold on this day...