The remarkable story of 43-year-old Sudan, the very last male northern white rhino on the planet. Aged just three, Sudan was snatched from his mother's side in Central Africa. He became a prized exhibit in azoo behind the Iron Curtain, while the rest of his kind was poached to extinction in the wild. Today, Sudan has become an unwitting celebrity and the focus of a desperate eleventh hour battle to save his sub-species. This astonishing modern day fable is told through the international cast of characters who have been involved in Sudan's life, for better and for worse.

David Attenborough is in the Swiss Jura Mountains to discover the secrets of a giant. Beneath his feet lies a vast network of tunnels and chambers, home to a huge empire of ants. It is believed to be one of thelargest animal societies in the world, where over a billion ants from rival colonies live in peace. Their harmonious existence breaks many of the rules for both ants and evolution, and raises some important questions. Through winter, spring and into summer, David turns detective to find the answers.