It has been nearly a year since Jack Winslow and his two sons, Colin and Andrew, set out to conquer Antarctica. While Colin and most of the crew stayed behind on the ship, Andrew made a dash for the South Pole, nearly dying in the process. When he returns to the Mystery, frostbitten and frail, the ship has become wedged between two ice floes. As the crew hacks at the ice with pick-axes, trying desperately to free the ship, the ice shifts, shattering the hull and giving the Winslows and their team just enough time to gather provisions before the Mystery plummets into the frigid water.