Synnott was joined by his wife, Hampton Synnott (at left), a U.S. Coast Guard–licensed captain who helped crew Polar Sun for part of the voyage. “Navigating in the Arctic is incredibly nerve-racking,” she says. “Picking our way through ice chunks and maneuvering around bergs that can calve or flip at any moment—you spend your life on boats avoiding these situations."

By the time Franklin set sail, the British had been searching for the Northwest Passage for three centuries. Each expedition pushed a bit farther north, sending the mariners’ compasses spinning in circles as they approached magnetic north. Their ships often became trapped in ice during the interminable darkness of the polar winter. Many expeditions ended in tragedy, but none so spectacularly as Franklin’s. According to the British version of the story, the Erebus and Terror were last seen by whalers off Greenland’s coast in July 1845—and never heard from again. A crucial clue emerged 14 years later. A private expedition financed by Franklin’s widow found a note tucked inside a metal cylinder at a place called Victory Point on the northern tip of Canada’s King William Island.

The Victory Point record, as it came to be known, is the most significant written account to emerge from the Franklin expedition. The note contains two separate entries. The first, dated May 1847, says the Erebus and Terror became trapped in ice eight months earlier, 15 nautical miles northwest of King William Island. It ends with: “Sir John Franklin commanding the Expedition. All well.” The second entry was added less than a year later and says the ships were abandoned in April 1848 and that the crew had lost 15 men and nine officers, including Franklin, who died two weeks after penning the first note. It ends by saying the surviving crew, now under the command of Francis Rawdon Crozier, intended to walk toward the nearest Hudson’s Bay Company trading settlement, more than 600 miles to the south. If there was any hope to be gleaned from this desperate note, it was that Crozier was a veteran of multiple Arctic explorations. He’d already endured an expedition that had been trapped in ice and spent time among the Inuit, who had given him the name Aglooka (Long Strider).

Back in London, however, the British had a very different view of the situation. In 1854, five years before the note was found, another account had emerged. John Rae, a Scottish fur trader and explorer, recounted meeting an Inuit named In-nook-poo-zhe-jook who said that a group of 35 or 40 koblunas (white men) had starved to death years earlier, near the mouth of a large river. The Inuit showed Rae dozens of relics they’d collected from the site, including a medal Franklin had received in 1836. But In-nook-poo-zhe-jook also described a camp that bore signs of Franklin’s men having been driven to what Rae called “the last dread alternative”: mutilated bodies, pieces of which still sat in kettles in which they had been cooked.