Matteo, a curious and adventurous dinosaur, finds a shiny leaf one day and decides to ride it down a hill into the unknown. As he slides down, he finds himself in total darkness at the bottom, eventually landing in a hidden cavern. There, he meets James, a friendly, wise dinosaur who guards the valley. Matteo learns that he's discovered the Hidden Caverns, filled with ancient treasures, strange creatures, and mysteries. Eager to explore, Matteo follows James, beginning an unexpected journey filled with adventure.