Following the story of American scientist and theoretical physicist J. Robert Oppenheimer (Cillian Murphy) and his role in the development of the atomic bomb in 1941.

Covered by the title of the Manhattan Project, Oppenheimer and the military built a remote city in the middle of nowhere in Los Alamos, New Mexico, where scientists could live for the next 18 months while they work to create an atomic bomb strong enough to win World War II and bring their soldiers home. They aim to fend off German forces, wanting to halt the invasion and genocide being committed by the country.