In 1914 Sir Ernest Shackleton and a crew of 27 men set sail for the South Atlantic on board a ship called the Endurance. The object of the expedition was to cross the Antarctic overland. In October 1915, still half a continent away from their intended base, the ship was trapped, then crushed in ice. For five months Shackleton and his men, drifting on ice packs, were castaways on one of the most savage regions of the world.