Events unfold on the eve of the New Year: a play is being prepared, children are waiting for gifts, adults are fussing. But a mysterious incident threatens to ruin the holiday for everyone at once. Varvara and her faithful friend Vasya immediately get down to business. Santa Claus himself helps them in the investigation, although he is not real. While everyone is talking about miracles, Varvara prefers to look for answers with the help of logic, because for her the New Year is a great reason to reveal another mystery.