Explore the scientific crescendo of the Manhattan Project through newly contextualized and never-before-seen photographs from Los Alamos National Laboratory's legacy collections--some just declassified. Twenty-one days before the world learned of the atomic bomb through its wartime use against Japan, a team of scientists led by J. Robert Oppenheimer detonated the first nuclear device on a remote stretch of New Mexico desert, in an operation codenamed Trinity. Both a military proof test and an elaborate, well-documented scientific experiment, the Trinity shot on July 16, 1945, brought under the control of humankind a new fire: the energy of the atom. In this expertly curated journey through the beginning of the atomic age, hundreds of carefully restored photographs, still frames, and once-secret documents bring new and vivid focus to a watershed moment in science and history. Written for all to understand, Trinity weaves steadily through subplots and surprises set against the evolving, looming backdrop of a world at war. It shadows the humans and hardware at work in the rugged landscape of the test operation; dissects a fiery mushroom cloud unfurling frame by frame, frozen in time; and follows soldiers, scientists, and two atomic bombs across the Pacific Ocean to Tinian Island, onto the strike planes Enola Gay and Bockscar, and to Hiroshima and Nagasaki, the two Japanese cities devastated on August 6 and 9, 1945. Inviting readers into the clandestine spaces where a new era began--behind the cameras, the bunker doors, the gates and guard posts--Trinity strives, grieves, celebrates, and ponders. It artfully captures that extraordinary summer when scientists invented urgently in the waning months of the "before"--and the tension between violence and progress, hope and fear, that persists into the after.