Jay Wechsler, who enlisted in the Army in 1943 and spent several months at Oak Ridge working as an Army construction engineer, was suddenly transferred to Los Alamos in the winter of ‘43 where he began working directly with Otto Frisch. Wechsler helped Frisch work on a large fission chamber that Frisch had originally designed in Denmark and later shipped to the United States. He recalls Frisch’s brilliant intellect and knack for solving problems, and discusses their long-lasting friendship over the years. Wechsler also discusses his role as an explosives expert at Beta Site, testing what would later become the implosion system for the plutonium bomb. Wechsler also recounts details of Trinity Test and discusses his opinion on the use of the atomic bomb on Japan and the lasting impact of atomic weapons. After the war, Wechsler continued his weapons work for the government throughout the Cold War.