On May 19, 1845, the HMS Erebus with its sister ship HMS Terror sailed out of the River Thames, carrying 128 officers and men under the command of Sir John Franklin. Their mission: to locate and transit the fabled Northwest Passage, the long-sought pathway from Atlantic to Pacific through Canada’s ice-strewn Arctic inlets.

It was a quest that had consumed some of Europe’s most accomplished mariners for almost four centuries, a generations-spanning obsession that chipped away at European understanding of North America’s high latitudes, sometimes at great cost to both vessels and lives.

With ice-strengthened vessels that had already proven their worth in the Antarctic, the Franklin Expedition was the best-equipped assault on the Passage ever launched. A little over two months after setting sail, the Erebus and Terror were spotted in Baffin Bay, just east of the Passage’s entrance; and then, they disappeared. None of the crew was ever seen by Europeans again.

What happened?

Rescue expeditions turned up tantalizing clues: A trio of graves at one site. A note at another site, dated April 1848 and indicating that Franklin and 23 others were dead, the ships had been trapped in the ice for 18 months, and the survivors were abandoning ship and striking out across land.

Other clues trickled in: An abandoned sled, with two skeletons and numerous personal effects. Letters from one of the men, some written phonetically and some backward and few fully deciphered. Stories from local Inuit of white men who had slowly perished; of ships that had been caught in, and then disappeared beneath, the ice.

For 170 years, such snippets were all that existed. And then, in September 2014, a search team found the wreck of Erebus, sitting in just 11 meters (36 feet) of water. Two years later, another team found the almost-pristine wreck of Terror, in deeper water to its companion’s northwest. And three years after that, the wreck sites’ first-ever visitors, passengers from the Adventure Canada-chartered ship Ocean Endeavour, watched as archeologists probed the Erebus for secrets.

The immediate and ongoing hope was that the discovery of the wrecks would fill in the missing pieces and shine a light on what happened to the Franklin Expedition. But at first, it only deepened the mystery—the wrecks were in the wrong place.

Terror was about 60 miles south of where the 1848 note said the ships had been abandoned, and Erebus was 30 miles farther south still.

Was it possible that, after setting out across land, at least some of the crew had a change of heart and returned to the ships to sail them south? Or is there another reason for their position?

According to Brandy Lockhart, an underwater archeologist with Parks Canada who has dived on both wrecks, it’s possible that the abandoned vessels were carried to their final resting places by the same ice that had entombed them. After all, she notes, “the overall ice break-up and drift pattern from where the ships were deserted is from north to south.”

But it is notable, Lockhart continues, that in the 19th century, “Inuit reported having observed signs of men on or about HMS Erebus prior to its sinking.”

While it may seem surprising that the ships should be found so far from where they were deserted, the Erebus wreck site is actually exactly where Inuit oral traditions have long said one of the ships sank. Initially, British officials gave short shrift to Inuit testimonies, repulsed by since-confirmed assertions that at least some of the desperate Franklin survivors resorted to cannibalism.

In more recent times, however, the import and accuracy of these testimonies has been increasingly acknowledged. Lockhart notes that, since 2018, “Parks Canada has been working on the Franklin Expedition Inuit Oral History Project, to gather existing oral histories related to the 1845 Franklin Expedition and the Inuit lands where the wrecks were found, from Inuit knowledge-holders, community members, and Parks Canada experts.”

We may never know exactly what happened to the crews of Erebus and Terror. The working theory remains that they died, one by one, succumbing to scurvy and exposure as they slogged vainly over land in search of safety. But, notes Lockhart, “Given the location of the two ships, it is clear that the interpretation of the Franklin story and how it unfolded has to be re-examined.”

In August 2019, remarkable video of HMS Terror showed a wreck that appeared to be frozen in time: intact cabins, an array of neatly-stowed artifacts, and closed drawers and cabinets. Perhaps behind those doors or in those drawers lies a crucial clue: a map, a letter, a journal. For almost 200 years, the fate of the Erebus and Terror has been a mystery; now, finally, maybe the ships themselves will help solve it.