On a dark night, De Scheve Schuit sails into a strange ship. When Piet and his friends take a look on board of this spooky ship, the crew appears to be cursed. They have all been transformed into stone statues! Piet wants to break the curse because he feels very attracted to the captain of the ship, Captain Marylin. It soon turns out that the solution is the ship itself; it's a flying ship! To make the ship fly, a blue pearl is needed. This can only be found on Oyster Island, an island inhabited by mysterious caves and carnivorous plants...