Returning to the park where he forgot his ball near a big cedar, Milo overhears a shadow that slips between the branches of the tree and runs away. The next day, Milo and his friends find their beautiful tree sick and want to solve the mystery. An expedition is organized and they discover a man pouring poison on the tree. He wanted to kill the tree to build a huge car park. The tree is saved and to celebrate this victory, children decorate the tree for Christmas.
