Interview about Egon Bretscher with his wife. Joins Ernest Rutherford at University of Cambridge in 1934. Work on nuclear cross-section measurements leads him to Los Alamos, at Niels Bohr’s request; collaboration with Edward Teller on hydrogen Bomb project. Plutonium work is discussed. Many anecdotes; comments on the Oppenheimer spirit at Los Alamos; the Trinity test, effect of Nagasaki bombing on him; his views on atomic energy in 1946 and 1966; retirement years. Also mentioned are: Chadwick, Klaus Fuchs, Otto Hahn, Hans von Halban, Lise Meitner, and Wolfgang Pauli.