The H.M.S. Terror Sank in the 1840s. See What It Looks Like Now.

About 170 years ago, a pair of English naval ships and their crew vanished while exploring in the Canadian arctic.

That disappearance, the basis for the first season of the AMC series “The Terror,” captivated England. Dozens of search missions were mounted in the years that followed, but the precise whereabouts of the ships remained a mystery until only a few years ago.

Now, new footage captured this month in the ice-cold waters of Canada’s Terror Bay reveals the strikingly well-preserved wreckage of one of those ships, the H.M.S. Terror, raising the tantalizing possibility that it may hold clues to what happened to the ill-fated expedition.

Among the questions it could answer is whether some of the 129 crew members returned to the abandoned ships to try to sail one to safety, said Paul Watson, a former journalist and the author of the 2017 book “Ice Ghosts,” which documents the history of the expedition.

“Did these ships just drift or did brave men go back to them and try to sail out, as sailors would?” he said. “Now, if that turns out to be true, I think it’s going to be an extraordinary and captivating story for the world.”

The new footage, released on Wednesday, was captured by Canadian government researchers this month during the first systematic scientific exploration of the sunken H.M.S. Terror since its wreckage was discovered in 2016. Its sister ship, the H.M.S. Erebus, was discovered just two years prior.

A seven-minute video shared by Parks Canada, the national parks service, shows the Terror’s ship wheel still upright, bottles and ornately decorated plates still sitting on shelves, and beds and furniture still in place. In the captain’s cabin, researchers found a work desk with sealed drawers that most likely hold documents containing crucial information about the expedition, including what went wrong.

The ships set sail from England on a Monday morning in May 1845 with a crew of 134 — five of whom were soon sent home — a cat, a Newfoundland dog named Neptune, and a monkey named Jacko, according to Mr. Watson’s book. Their aim, under the command of the explorer Sir John Franklin, was to chart a northwest passage to India and China.

The expedition had made its way into Canada’s Arctic Archipelago before being trapped in sea ice just off King William Island on Sept. 12, 1846. Franklin died the next year and, in 1850, the British Royal Navy commenced a full-scale search for the ships and crew, Mr. Watson wrote.

Sparse, but intriguing clues had surfaced over the years, but the search for information reached a turning point in 1859 with the discovery of the Victory Point Note. On it were two handwritten messages, according to the Canadian Museum of History. One, signed by Franklin in May 1847, provided a brief update on the expedition’s whereabouts, concluding with the words “all well.” The other, written in April 1848, reported that two dozen people, including Franklin, had died and that the ships had been trapped in ice for 19 months.

Other clues, including reports of sightings and encounters with native Inuits, emerged over the years, but countless questions remained, Mr. Watson said. What happened? Did the expedition ever discover the northwest passage? What caused the ships to sink? What did the crew do to survive?

“It sets up an extraordinary mystery. How can 129 sailors of the Royal Navy all perish?” he said.

The discovery of the ships in recent years, though, represented a significant breakthrough in that search for answers.

On Aug. 7, Parks Canada in partnership with local Inuits dispatched an underwater archaeology team to the site of the Terror to research and create a 3D map of the wreckage.

Over the course of a week, the team explored inside the ship with a remotely operated vehicle, obtaining clear images of more than 90 percent of the lower deck, including the captain’s quarters, much of it well preserved by the cold water, lack of light and layers of silt. As a result, the agency predicted in a statement that there is a “high probability” of finding written documents preserved within.

“Not only are the furniture and cabinets in place, drawers are closed and many are buried in silt, encapsulating objects and documents in the best possible conditions for their survival,” Marc-André Bernier, manager of underwater archaeology for Parks Canada, said in a statement. “Each drawer and other enclosed space will be a treasure trove of unprecedented information on the fate of the Franklin Expedition.”