We're Not Made of Cardboard

Lisa loves the canoe that Santa built for her, and although the girl is forbidden to communicate with the old man, she still considers Santa her grandfather, as he has no one else. And she has her mom, Pashka, Sonya, Stasya, Kanyusha, and other kids from the Center, where she has to spend the night.
But one day, the swims come to an end, and the old man disappears without a trace...