The young commander shuffled along, head down and eyes glued to the compass, as the frigid wind and blowing snow stung his face. Counting a hundred paces, he stopped and peered about. With an initial sense of relief, he spotted the first marker post through the cottony swirls. Moving alongside the post, he took another bearing and proceeded to the next marker. The string of men leapfrogged from marker to marker, clambering over uneven mounds of snow that often rose thirty or forty feet high. Fitzjames focused all his energy on the journey, shaking off the disappointment of abandoning his ship to a contingent of madmen. Deep down, he knew it was a matter of survival. After three years in the Arctic, nothing else now mattered.

Then a deep boom shook his hopes. The sound was deafening, even over the howling winds. It sounded like the report of a large cannon, but the captain knew better. It was the ice beneath his feet, layered in massive sheets that moved in a rhythmic cycle of contraction and expansion.

Since the two expedition ships had become trapped in the ice in September 1846, they had been propelled over twenty miles, pushed by the massive blanket of ice called the Beaufort ice stream. An unusually frigid summer kept them icebound through 1847, while the current year’s spring thaw had materialized only briefly. The ravages of another cold spell again made it doubtful that the ships would break free over the coming summer. In the meantime, a shift in the ice could be fatal, crushing a stout wooden ship like it was a box of matches. In another sixty-seven years, Ernest Shackleton would watch helplessly as his ship the Endurance was crushed by an expanding ice pack in the Antarctic.

With his heart racing, Fitzjames increased his pace as another thunderous crack echoed in the distance. The rope in his hands grew taut as the men behind struggled to keep up, but he refused to slow. Reaching what he knew was the last marker pole, he squinted into the tempest. Through the blasting swirls of white, he caught a brief glimpse of a dark object ahead.

“She’s just before us,” he shouted to the men behind him. “Step lively, we’re nearly there.”