5th grade student Masha Kametova learns that she will be left at home alone for several days because her parents are leaving on an urgent business trip. A nanny was called to look after Masha, who was found through a fashionable online service. However, who would have guessed that a professional nanny had an insidious plan? As soon as Masha realizes this, she decides to use modern gadgets to bring the criminal to light and show her who is boss in the smart home.