When a friend of Geoff's accidentally discovers a remarkable, and previously unknown, stone meteorite near the Mexican border, the guys head back to southern Arizona to investigate the new find. Local hunters, Greg and Wendy, join the MM in the field, as does Arizona State University meteorite specialist Dr. Laurence Garvie. A piece of the new meteorite goes through the exacting process of examination and classification in the ASU lab. Also, Geoff takes time out from the hunt to chat with a horned toad, and Steve learns the perils of riding a mountain bike in the Arizona desert.