The Amazon is one of the wildest and least explored parts of the planet. Encompassing 6 countries and 2 million square miles of forest, river and floodplain, it has the highest diversity of life on the planet, but what lies below it is truly shocking. In its deep muddy rivers, clear streams and expansive floodplains a freak-show of fish life has exploded, with some of the strangest shapes and weirdest adaptations on Earth. Hiding in the vast rivers and streams is an electric grid, a bizarre community of fish with a highly sophisticated electric sixth sense. Using electricity, these "Super" fish can communicate wirelessly, control each other remotely and emit shocks that can stop a human heart. This cryptic world has mystified scientists throughout the ages. Now an intrepid scientist, Will Crampton ventures back into the dark jungles where the inspiration for our technology driven world first emerged, in an attempt to unravel their secrets and unlock the electric code.

A caving expedition recently discovered a community of dwarf crocodiles living in the Abanda Caves, Gabon. The crocs are living in pitch darkness, hunt bats and some have bright-orange skin. Part of the original team returns to find out more about this bizarre phenomenon. It's mission impossible to access the crocs world and there's no way of knowing what they might find.

Tasmania lies on the Australian continent, but is a world apart. It is home to an extraordinary cast of black devils and white wallabies. Trees here tower to one hundred metres and green lights dance in the southern sky. As the last landfall heading south before Antarctica, Tasmania's isolation, cooler climate and distinct seasons influence everything.