What makes sharks built for speed? How do snakes move without limbs? How do sugar gliders fly without feathers? The answer all lies in their skin. Professor Ben Garrod uncovers the secrets of how skin has evolved to enable animals to solve some of the most remarkable challenges on earth. To do this, Ben heads to the specialist flight centre at the Royal Veterinary College to analyse the way a sugar glider uses its skin flaps to stay aloft. He goes diving with sharks at the Blue Planet Aquarium and discovers that, far from being smooth, sharkskin is incredibly rough. It is covered with thousands of tiny teeth that make a shark hydrodynamic. Ben also finds out how the keratinised scales on snakes' bellies are the perfect configuration to allow them to move over virtually any surface they encounter. Amongst many other wonders of how skin has had an impact on nature.