Egor`s parents hire a new nanny to take care of his newborn sister after the family moves to an apartment on the city`s outskirts. He notices the nanny exhibiting strange behaviours but his parents ignore him when he tries telling them, choosing to believe instead in the nothing-out-of-the-ordinary happenings that they can see via the surveillance cameras. When the nanny mysteriously disappears along with his sister and his parents even more mysteriously forget the baby`s existence, he works with his friends to look for her. He is horrified to learn that the nanny`s true identity is Baba Yaga, an ancient Slavic demon.