On this journey, Martin wants to find out how the horse became so important to us. On the walls of the Niaux Cave, hidden high in the Pyrenees Mountains, Martin finds an extraordinary 14,000-year-old record of how our relationship with horses began. He also meets the famous horse whisperer Monty Roberts to learn how to improve his relationship with Chester, and understand how that mysterious bond allowed us to communicate with horses in the first place. Finally Clunes joins Laura Lee, Nevada resident and lover of the wild American mustang. In a helicopter they fly over the high desert in midwinter, to catch a glimpse of the mustang herds running free in their natural habitat, the way all horses once lived.