When nuclear fission is discovered in 1938 after the Germans succeed in splitting the atom, Oppenheimer realizes it can be weaponized. In 1942, during World War II, US Army Colonel Leslie Groves, the director of the Manhattan Project, recruits Oppenheimer as the director of the Los Alamos Laboratory to develop an atomic bomb. Oppenheimer fears the German nuclear research program, led by Heisenberg, might yield a fission bomb for the Nazis.