Since the discovery of British mountaineer George Mallory on the icy north face of Mount Everest in May, the world has learned a bit more about what happened on his fateful climb back in 1924. But still, the biggest question remains unanswered. Did Mallory and his partner Andrew Irvine make it to the summit? If they did, they would have accomplished the feat decades before Edmund Hillary and Tenzing Norgay. Everest climber Eric Simonson organized the team that set out to find Mallory this spring. He's just released a book about the expedition called "Ghosts of Everest." Simonson says the sketchy information he and other climbers have had over the years fueled their imagination and hope that Mallory made it.