Hungarian physicist Leo Szilard leaves Europe, eventually arriving in the United States. With the help of Einstein, he persuades the government to build an atomic bomb. The project is given to no-nonsense Gen. Leslie Groves who selects physicist J. Robert Oppenheimer to head the Los Alamos Laboratory in New Mexico, where the bomb is built. As World War II draws to a close, Szilard has second thoughts about atomic weapons, and policy makers debate how and when to use the bomb.
Gen. Leslie Groves
J. Robert Oppenheimer
Leo Szilard
James F. Byrnes
President Harry S. Truman
Gen. George Marshall
Henry Stimson
Dr. Arthur Compton
Franklin D. Roosevelt
Kitty Oppenheimer
Colonel Pash
Edward Teller
Dwight D. Eisenhower
Groves's Commanding Officer
Ralph A. Bard
Enrico Fermi
Colonel Nichols
Richard Feynman
Hans Bethe
Klaus Fuchs
Lord Rutherford
Michael Polanyi
Colonel Lansdale
Robert Wilson
Mrs. Wisnovsky
Jack Wisnovsky
Mrs. Trowbridge
Robert Serber
Ed Condon
William 'Deke' Parsons
Captain DeSilva
Army Major
Kenneth Bainbridge
Chemist
Army General
Scientist (uncredited)
Leo Szilard's Prime Scientist (uncredited)
Producer
Executive Producer
Director