An imposing castle towers above a smaller neighboring fortress, both completely surrounded by dense woods. When the lord of the fortress, Martin of Vamberk, is called to war, he leaves the estate in the hands of his eldest son Peter. Unfortunately, Peter's poor manners lead his subjects to grow discontented, causing his siblings to ensnare him in more or less successful traps. Meanwhile, Lord Albrecht of Krvenos devises a plot to overtake the fortress. The children's lives are turned upside down as they fight for their livelihood and their castle.