Bert's scantily dressed neighbour downstairs, Klaasje, comes by to borrow a cup of sugar, the old clichéd situation with a quite possibly sexual outcome. When she lets the cup slip from her hands and they both try to catch it, destiny strikes.

By an unfortunate twist of fate, Ernst and Bobbie end up on a giant cruise ship. The captain seems to have disappeared, and of course, Ernst and Bobbie set out to find him. But then they discover that a villain is on board! Their search leads them to a tropical bounty island — where the captain is hiding...