Scientists and explorers travel to the Arctic to reveal the unknown world of icebergs, starting with the birth of an iceberg at Greenland's Store glacier.

In the first programme, the team uncover the hidden forces that explain why the Store Glacier of Greenland produces so many icebergs. Naturalist Chris Packham works with scientists on a research yacht in the danger zone at the front of the glacier, whilst ocean specialist Helen Czerski explores the inside of the glacier itself. During the expedition the team witness the creation of an iceberg as a multimillion-ton block of ice bursts forth from the glacier.