"Irvine and Mallory were last seen on June 8, 1924, while attempting to become the first people to reach the top of the world’s highest peak. The question of whether they had summited has endured as the greatest climbing mystery of all time. If Irvine and Mallory succeeded, their feat would have come some 29 years before Tenzing Norgay and Edmund Hillary finally reached the top of Everest. "