Everest hid the body of a climber for a century. The rediscovery of his corpse could upend our understanding of the peak.

One morning in October 2024, the writer Julie Summers received a call at her home in Oxford conveying astonishing news. A boot containing the remains of a human foot had been found on the north flank of Mount Everest.A woolen sock tucked into the boot bore a white name tape, with red letters spelling out: A.C.

IRVINE. Andrew Comyn “Sandy” Irvine, a 22-year-old college student who accompanied British mountaineer George Mallory on his ill-fated attempt to summit Everest, had been lost for more than a century.Noel Odell, a fellow Everest expedition member, was the last person to glimpse him and Mallory — as two black spots far in the distance “going strongly for the top” along the mountain’s crenulated ridgeline on June 8, 1924. When mist moved in, engulfing the pair, they vanished, never to be seen alive again.

Only in 1999, when Mallory’s mummified body was located in Everest’s high-altitude “death zone,” 2,000 vertical feet below the peak, did investigators begin to piece together the valiant climbers’ fate. No trace of Irvine had been found — until now. For Summers, the grandniece of Irvine, and his biographer, (“Fearless on Everest: The Quest for Sandy Irvine” was published in 2000) learning of the find was “a shocking, extraordinary moment,” she told The Post.She soon felt the desire to revisit her great-uncle’s life story, and embed it in all that had been learned in recent years about the 1924 venture and its aftermath.

She asked her friend Jochen Hemmleb — the author, climber, and mountaineering historian who had been part of the research expedition that located Mallory’s body — to collaborate with her.As befits its dual authorship, “The Everest Mystery: Sandy Irvine, George Mallory, and the Truth Still Buried on Everest” (St.

Martin’s Press, Aug.25) is two books in one. In the first half, the writers draw a engaging portrait of Irvine, traditionally regarded as somewhat of an “also-ran” on the missi...