The Carpathian mountains are criss-crossed by hundreds of streams making their way down into the valleys. Vlčí potok, the Wolf Brook, is one of them. As it descends, it creates dozens of small pools. Although they seem empty and deserted, they have been full of life since primaeval times. Each of them is host to the countless goings-on of their remarkable inhabitants. They are mostly inaccessible to humans, and this is maybe why we have been unable to protect such a fragile and vulnerable world from ourselves. Starring a rare fish called the Alpine Bullhead.