A team of intrepid paleontologists discovers that dinosaurs thrived in the unlikeliest of places—the cold and dark of winter in the Arctic Circle. How did they survive year-round and raise their young in frigid and dark winter conditions? A dinosaur expedition explores a remote, treacherous, and stormy terrain where the team knows that every bone they find there will likely be a first, adding up to a unique picture of a lost northern world.

Colossal explosions shake a remote corner of the Siberian tundra, leaving behind massive craters. In Alaska, a huge lake erupts with bubbles of inflammable gas. Scientists are discovering that these mystifying phenomena add up to a ticking time bomb, as long-frozen permafrost melts and releases vast amounts of methane, a potent greenhouse gas. What are the implications of these dramatic developments in the Arctic? Scientists and local communities alike are struggling to grasp the scale of the methane threat and what it means for our climate future.