Peter Lax fled Nazi persecution in Hungary and came to America with his family at age 15. Drafted into the Army at 18, he joined other émigré scientists and mathematicians in Los Alamos to work on the Manhattan Project. In this interview, Lax discusses his work as a member of the Manhattan Project's Special Engineer Detachment and work on neutron transport, fluid dynamics, and shockwaves. He vividly describes what life was like at Los Alamos and offers insights on the development of scientific computing and atomic energy. He also recalls the "Martians," the brilliant Hungarian mathematicians and scientists who worked on the Manhattan Project. 

Colonel Franklin Matthias was the officer-in-charge at the Hanford site. In the second part of his interview in 1965 with Stephane Groueff, Matthias describes the personalities of the men he worked with, including Enrico Fermi and DuPont's Granville Read. He recalls a visit by Fermi and Eugene Wigner to Hanford, and explains why Read got along well with General Leslie Groves. Matthias discusses the safety measures at Hanford, and recounts how a Japanese fire balloon temporarily knocked out power to the plant. He also explains how scientists conducted tests on salmon to assess levels of radioactive contamination in the Columbia River.

General Kenneth Nichols was the District Engineer for the Manhattan Engineering District, and oversaw the design and operation of the Hanford and Oak Ridge sites. He was responsible for securing the initial deals with Stone & Webster and the DuPont Company to develop the industry for the site, and lived for a time with his wife at Oak Ridge. In part 3 of his interview in 1965 with Stephane Groueff, he discusses sabotage and Klaus Fuchs, dealings with the British, and the very start of the Manhattan Project. He recalls some conflict between the scientists and engineers, the importance of industry in the project, and the initial problems with the startup of the B Reactor.

Sir Rudolf Peierls was a German-born physicist. He worked with Wolfgang Pauli in Switzerland, and moved to England when Hitler rose to power in 1933. In March 1940, Peierls and fellow colleague Otto Frisch co-authored the Frisch-Peierls memorandum, the first technical exposition of a practical atomic weapon. Peierls joined the British Mission and worked on the Manhattan Project in New York and Los Alamos. In this interview, Peierls discusses his work in atomic research and how the Frisch-Peierls memorandum was developed. He recalls going sailing with Oppenheimer, and how the scientists at Los Alamos respected Oppenheimer's leadership.

Colonel (later General) Paul Tibbets was the pilot of the Enola Gay, the B-29 that dropped the "Little Boy" atomic bomb over Hiroshima on August 6, 1945. In this documentary Tibbets co-produced with the Buckeye Aviation Book Company, "Reflections on Hiroshima," he recounts his memories of the day the atomic bomb was first used in warfare. Tibbets recalls how he became a pilot, and explains how the Manhattan Project's "Silverplate" program produced a special version of the B-29 capable of delivering the atomic bomb. He also discusses the target selection process and describes the "odd couple" of J. Robert Oppenheimer and General Leslie Groves. He remembers seeing the mushroom cloud over Hiroshima and feeling the shock wave of the blast, and shares his views on the role of morality during war.