Mallory and Irvine. One of the great mysteries of mountaineering is whether they reached the summit of Everest in 1924 before disappearing some 26,000 feet up on the brutal north-east ridge. For 75 years the mystery has remained unsolved. Julie Summers set out to learn about Sandy Irvine, the mysterious great uncle who perished. She has uncovered previously unknown letters and photographs, which show his determination to reach the summit, come what may. An expedition is being mounted to find Irvine's body. And there is the hope that the cine camera that Irvine had with him might be near the body. If it is then according to Kodak, who supplied the film, the cold will have ensured that any images can still be viewed. And if Mallory and Irvine had succeeded in reaching the summit then there could be film to prove it.