Exactly what Noel Odell saw that day has never been definitively established.

Looking up at the vast, frozen peak of Mount Everest, Odell – a member of the 1924 British expedition that aimed to be the first to reach the summit – reported seeing two small dots ascending a rocky step that was within a few hundred metres of the top. They were moving swiftly, without haste, making what Odell would later describe as a strong push towards their target. A cloud then passed over the mountain, and the dots were gone.

The two dots were almost certainly George Mallory and Andrew Irvine, two of Odell’s expedition companions. Mallory was a skilled mountaineer who had attempted to summit Everest twice before. Irvine, aged just 22, lacked Mallory’s years of experience but his extensive engineering knowledge, which he utilised to make improvements to the expedition’s equipment, made him a valuable member of the team.

It’s possible that Odell saw nothing more than a few rocks, combined with shadows and a distance of more than 3000 feet to create the illusion of moving figures. The exact location of the dots would later become the subject of controversy, with some researchers suggesting they were further down the mountain than Odell initially asserted.

But if Odell was right, and he had seen the pair making a valiant bid towards the summit of the mountain, he has a place in history as the last man to see them alive.

Mallory and Irvine never returned to their base camp. They vanished on the mountain, and whether they made it to the summit – becoming the first humans to do so – is unknown.  

With the exception of an ice axe in 1933 and a dilapidated oxygen cylinder in 1991, no trace of either man was found for more than 75 years. Edmund Hillary and Tenzing Norgay became the first mountaineers to undisputedly reach the summit of Everest in 1953, and numerous others have followed in their footsteps, but speculation that Mallory and Irvine had beaten them to the punch continued to swirl.

It was not until 1999 that a major breakthrough was made: the discovery of Mallory’s body. Frozen and mummified, it was lying face-down on a rocky slope, the head almost completely concealed by rocks, but the atmospheric conditions meant it was remarkably well preserved. Initially, the team who found it believed they had discovered Irvine and only realised their mistake when a name tag attached to a disintegrating shirt identified it as Mallory. Although a number of personal effects were recovered, nothing was found to prove they had reached the summit. The team said a prayer, covered the body with stones, and left; it remains on the mountain to this day.

Irvine’s body has never been found. In the 1970’s, a Chinese climber named Wang Hong-bao claimed to have found a decades-old body near the Northeast Ridge of the mountain, lying on its side and with a large puncture wound in the cheek. (For comparison, Mallory was found lying face-down and did not have a cheek injury.) He was adamant the remains belonged to an English person because of the old-fashioned clothing, and Mallory and Irvine are the only English climbers known to have died in that general area. In an ironic twist of fate, Wang was killed in an avalanche the following day, before the location could be more accurately determined.

We don’t know if Mallory and Irvine made it to the summit, but there is one final element to this story that could provide an answer: a battered, portable pocket camera.

Mallory and Irvine were known to be carrying at least one camera when they made their final ascent. Despite an extensive search, it was not found on Mallory’s body, suggesting it may have been in Irvine’s possession when the two disappeared. Given the frozen conditions on Everest and the type of photographic film within the camera, there is a reasonable chance that any images could still be developed if the camera is recovered safely. Perhaps, as many hope, it will contain evidence that the two had reached the summit. But until Irvine’s body is recovered, or the camera is found elsewhere on the mountain, we will never know for sure.

Then again, we might never definitively know either way. There are more than enough people invested in this mystery to keep it going, regardless of any future developments. Even if the camera is found, and there is no view from the summit present on the recovered film, someone will almost certainly claim they dropped it before reaching the top. In that sense, the story will live on.

You can draw your own conclusions about what happened on that day, but I’ll leave you with one final point. Mallory carried a photograph of his wife with him at all times during the 1924 expedition for the sole purpose of leaving it on the summit. Just two items were missing from Mallory’s exceptionally well-preserved body when it was discovered in 1999: the camera, which was probably in Irvine’s possession, and the photograph. Circumstantial evidence, of course, but it makes the mystery just that little bit more intriguing.