In 1847, British explorer Sir John Franklin and his crew disappeared while searching for the Northwest Passage. A Nat Geo team sought to find evidence of their fate... but not without obstacles of their own. The team sailed from the Atlantic into a mazelike network of channels toward the other side of the continent, off the coast of Alaska. Along the way, their boat became trapped in ice floes, and with winter approaching, they—much like the ill-fated Franklin expedition—risked being stranded in