What Do Grandmothers Hide?

Andrei is already seven years old, and from the height of his life experience, it becomes obvious to him that grandmothers are very different from other adults. To unravel this mystery, he conducts a real investigation and finds out: where do grandmothers know everything about everyone from? Where have they put their own teeth? Where are grandmothers going so early? Does Grandmother Frost exist? He also finds answers to other equally important questions.