The main character, Adam Tsisowski, is seventeen. He was nicknamed the Devil not for his bad behavior, but for the fact that he knows how to solve very complex, seemingly unsolvable problems. And he is not a devil at all, but a sincere, honest, responsible and brave guy. The events – mysterious, adventurous, detective – begin in Warsaw, and then move to a noble estate near Vilnius. Adas and his friends, unraveling secrets and riddles, look for answers in the events of 1813 and 1863.