Long rivers of snowmelt water flow on the ice sheet of Greenland's inland and they melt in the summer and freeze in the winter. The rivers have moulins, several hundred meters deep, vast vertical shafts. The scientists in this film try to go in one to find out about the future of the Earth that's warming up so fast. To be prepared for the future, Jason Box and the scientists chose to walk the 'ground truth' rather than the slow way of sitting in front of the computer and analyzing the data. They say walking into the ice is like walking into the history of climate. Following them in this expedition, we will soon meet the world in the ice, the center of the climate history.