When Rico's nasty neighbor dies, he surprisingly inherits the grump's gemology collection. Soon one unpolished prize piece is stolen, so Oscar helps him, while mother and Simon are on foreign holiday, to follow the trail to the Baltic, posing as bathing resort tourists, even suitable (un)dressed at a nudist beach. Enlisting help from the yuppie gay Berlin neighbors couple, the sleuth knaves must rush home, having discovered the fence isn't pleased as the thieves took the wrong stone.