At 8:16 in the morning on August 6, 1945, the atomic bomb Little Boy detonates 587 meters above Hiroshima, Japan. The film reconstructs that morning and the years that follow, tracing the physics of the blast, the immediate destruction of the city, and the long medical and political aftermath for survivors and the nations involved. Archival footage and photographs of the ruined city sit alongside interviews and expert accounts that walk through the decision to use the bomb, its immediate effects on the ground, and the decades of debate over its necessity and legacy. The film treats the bombing as both a singular historical event and the opening chapter of the nuclear age, following how Hiroshima shaped weapons policy, memory, and public understanding of nuclear war in the decades since. It stays close to the timeline of that single morning before widening out to the bomb's global consequences.