 Teddy and Freddy take their new friends Niklas and Johan on a trip to one of the rocky islets in the outskirt of the archipelago. They also take Båtsman with them, which makes their little sister Tjorven angry, because it s her dog. When Tjorven s parents don t recognize her complaints, she decides to leave the family and become a housekeeper to Söderman. Johan moors the boat too loosely at the rocky islet and when the four young friends are eating fish by a fire, the boat drifts away. Their boat is saved by the girls teacher Björn, who happens to be in his boat in the neighbourhood.