Touch is expressive, intuitive and complex in design and function. No sense defines us more. And yet most of us move through life completely unaware of the myriad ways we use it. Take a journey through the skin, into the subcutaneous world of our sensory receptors and into the brain, to explore the hidden language of our most essential sense. Along the way meet Ian Waterman, a man who's developed some amazing strategies to compensate for the loss of his sense of touch. And discover what a race car driver and a surgeon have in common when it comes to using this extraordinary sense.