Lila and Franek loved to play in the tree house they built together with their dad. Every day after school they climbed the old branches of the big oak tree and made up all sorts of adventures. One evening, as the sun was setting, Lila looked out of the window of her room and saw a a strange flash in the tree house! "Frank, do you see what I see?" - she asked in a whisper. Franek came running over and also spotted the glowing speck. The children quickly threw on their sweatshirts and quietly slipped out of the house. As they approached the tree, they saw that the house was as if lit up from inside. The door was slightly ajar and there was a mysterious, flickering light coming out from inside that they had never seen there before. Lila squeezed Frank's hand tightly. What could it be? Was it just a skylight or something completely special? Just then, the door of the cottage creaked even wider, and a quiet rustling sound came from behind it....