Piet Piraat, Stien Struis, Berend Brokkenpap and Steven Stil travel with the flying ship 'De Wankele Walvis' to a tropical island. They have to battle flesh-eating plants and a giant laughing oyster. They discover some petrified pirates, including the beautiful pirate captain Marylin. Piet Piraat falls in love with her and tries to save her.