The Arctic: a Cold War battleground hiding remarkable secrets. ‘Camp Century' was like something out of sci-fi: a US Army base under the Greenland ice cap. Lost and forgotten for 50 years, climate change may bring the camp and its dangerous waste back to the surface. While deep beneath Arctic waters is the ghostly wreck of a long sunk Soviet nuclear submarine that may be leaking radiation. Cutting edge science teams take on these toxic legacies.