Uranium saves lives, treats cancer and brings hope to millions. Uranium was also a promise of clean limitless power. In a remarkable and haunting journey, Dr Derek Muller takes us to Chernobyl and Fukushima, where uranium became a nightmare. In our energy-hungry, warming world, uranium both tempts with unbelievable power and threatens all life on earth. Destroyer and saviour, dream and nightmare: the extraordinary paradox of uranium.