He gets to give the letter to the Czarina and the only thing that remains following his ordeal is the fact that once a year, on the date he met the group of demons, his wife has an uncontrollable urge to dance and does, with no way of stopping her.
He encounters a group of demons and endures a difficult situation. As a result, his wife experiences an uncontrollable urge to dance every year on the date of their encounter with the demons.