Once every hundred years, the night comes in Russia, which is popularly called the "Hour of the Immortal". It is believed that at this moment the border between the worlds is thinning, and Koshchei comes out of his dungeon to remind mortals of the ancient contract. Once, in times of frost and famine, he appeared to people and said: "I will save your family, but you will pay me for this with the most valuable sacrifice - girl's beauty." Since then, every village knows: if you neglect the custom, trouble will come - the harvest will fall, the cattle will die, the disease will mow everyone down.

On the chosen night, the most beautiful girl is dressed in white, like for a wedding, and taken out of the village - to the old oak near the border of the forest. Red ribbons are woven into her braid - a symbol of blood and a vow. She is no longer at dawn: Koshchey takes the bride to his kingdom, beyond the Smorodina River, from where there is no road. Some say that he destroys her and nourishes his immortality with her soul. Others whisper that he takes a wife to forget his loneliness for a moment. But no one came back to tell the truth.