For Arg, a boy of high intelligence living in the Stone Age, being smarter than everyone in his Neanderthal tribe makes it hard to fit in. When it seems that no one will ever understand him, he meets Skeet, an equally evolved, talking T-Rex, and is alarmed when he learns of Skeet's concerns about the dwindling population of dinosaurs. They decide to join forces and embark on a mission to save dinosaurs from extinction.