By the end of the war, she wrote, there was no one left to dance with. Vera Brittain, a nurse, lost her fiancée, Roland, her two best friends from Oxford, and finally her beloved brother Edward. On foot over several months I retraced all the Tibetan approaches to the mountain, climbing to heights in a deliberate attempt to experience the severe effects of oxygen deprivation. Archival research led to 57 institutions in several countries my research library grew by more than 600 books. What each had endured was ascertained from regimental diaries, letters, and journals. Over twelve years I found out where each man had been every day of the four years and four months of the war. To pursue this theme, I had to show, not tell, what the war had implied. An answer came in a single phrase uttered by one of the survivors as they retreated from the mountain: “The price of life is death.” Mallory walked on because for him, as for all of his generation, life mattered less than the moments of being alive. But what interested me from the start was not whether Mallory reached the summit, but rather why on that fateful day he kept going. In 1924 Mallory and Irvine were last seen going strong for the top as the mist rolled in and enveloped their memory in myth. Of the 26 British climbers who walked 400 miles off the map to find and assault the highest mountain on Earth, twenty had seen the worst of the fighting. If the quest for Everest began as a grand imperial gesture, as redemption for an empire of explorers that had lost the race to the Poles, it ended as a mission of regeneration for a country and a people bled white by the Great War. Into the Silence tells the story of the British Everest expeditions of 1921-24, against the backdrop of Tibet and the Raj, and in the wake of a war that had changed everything. Winner of the 2012 Samuel Johnson Prize (the precursor to the Baillie Gifford Prize) for Into the Silence: The Great War, Mallory and the Conquest of Everest

Read on below to find out more about their groundbreaking work. The shortlist includes some of the most important nonfiction writers working today: Patrick Radden Keefe, Wade Davis, Barbara Demick, Margaret MacMillan, James Shapiro, and Craig Brown. In honor of its 25th anniversary, the Baillie Gifford Nonfiction Prize will announce on Thursday its “Winner of Winners” award, which singles out the best of its annual prize-winners over the last quarter century.

Goodbye, Darkness by William Manchester