On a late summer afternoon, Hilda and Belaba start walking. Upon arriving at a grove, Hilda looks at a strange keyhole-shaped burrow on a tree trunk. According to Belaba, not only that, but indeed it is. And if so, there must be a matching key somewhere! A mole comes out with a big key. Bela asks him to insert it into the keyhole and turn it. At first, the two muffins believe that nothing has happened, but then, on the contrary, it turned out to be a big problem: the whole meadow was on its head!