After a violent storm, Captain Eksteroog lands on a desert island. He wants to find the treasure that his sworn enemy Zilvertand has buried there. But he is not alone on the island. Reus, a 2m-tall giant has also arrived there with five children and their dog. Eksteroog decides to kidnap the dog in order to force the children to come and work for him and find the treasure. At the same time, Piet Piraat and his friends discover by accident an island that isn’t on their map.