WWII's scale and fear of atomic power set the stage for a race to create new weapons.

Groves and Oppenheimer unite allies across continents to form the sprawling Manhattan Project.

Uranium gun-type and plutonium implosion approaches converge, leading to the Trinity test.

Interim Committee and Chicago scientists debate how, when, and whether to use the bomb.

The first atomic bombs unleash unprecedented destruction and force Japan toward surrender.