Friendship is not that simple and Julka knows it well. She's 12, goes to boarding school and has never had a real friend before. The holidays are starting, and with them comes trouble. Instead of going to her parents in Canada, Julka goes to her aunt in Warsaw. Olek lives in the same tenement house. When the kids come up with a plan to find the treasure, the adventure begins. Standing in the way of solving the mystery are a gang of thieves, a nanny who is a heavy smoker and a suspicious candy eater. No one is who they say they are, and the race against time continues. To get out of this story alive, Julka must overcome distrust and dare to be friends.