Berlin has a vast network of lakes, rivers and canals, integrated into the urban landscape. In fact, it is often said that Berlin has more bridges than Venice. And like Venetian bridges, Berlin's waterways present an ideal breeding ground for a child’s vivid imagination. It is no wonder then, that the pirate is one of the favorite characters in the games children play. There is a pirate hidden in each Berlin youngster and he is just waiting to come out for his next urban adventure - much to the despair of the adults watching these wild shenanigans.
The film series revolves around four of these city pirates: identical twins Marie and Louise Kukowski (both fourteen years old), their brother Matt (eleven years old) and his sister Babette (eight years old). All four are experts in looking for trouble.