Three teddy bears: Kuba, Misia and Bartek, decide to spend their summer holidays in a joyful and constructive way. Accidentally, they end up on an island-reserve. During one of their plays, they unintentionally hurt the Viper. As a punishment, the Wood Tribunal sentences the visitors to a forced labour for the benefit of the inhabitants of the reserve. Miss Misia takes care after tiny Mice, Bartek cleans the Hamster’s pantry, whereas Kuba helps the Beaver.