On Luxembourg City’s pirate ship playground, while two brothers pretend to be daring pirates, they discover an old parchment complete with treasure map! They set off on a treasure hunt, but before long, get into a fight. Each one goes his own way, hoping to get there first. Mysteries and maps lead to their discovery of the old city and its history. But it is only when they reunite and join forces that, together, they succeed in finding its incredible treasure.