Andy travels back 65 million years to the time of triceratops, a plant-eating dinosaur which roamed the plains of North America. His mission is to find a triceratops horn to replace the one he broke back at the museum. Along the way he comes face-to-face with the mighty T-rex and meets an ankylosaurus, another plant-eating dinosaur covered in huge armoured spikes. Then he sees two triceratops battle to become leader of the pack. But, will Andy find a horn and get back to the museum in time before it opens?