Le Trésor tells the story of a young boy who embarks on a solo journey aboard a sailboat and discovers a secret island, only for a darker reality to surface. The film serves as a poignant environmental allegory, shifting from a beautiful nature fantasy to a terrifying twist where a boy realizes that this vibrant ecosystem has disappeared in a not-so-distant future. It stands as a striking reminder that nature and our planet are the most valuable treasures humanity must protect.