Warren Nyer is one of very few physicists who worked at all four main sites – Chicago, Oak Ridge, Los Alamos, and Hanford – of the Manhattan Project. He began working on the classified project at the young age of nineteen. He discusses his interactions with Oppenheimer and Fermi, along with the excitement of viewing the world’s first nuclear test at Trinity. Nyer also describes his living situation at Hanford, from the dormitories to the houses. Finally, he offers his justification for the use of the atomic bomb in Hiroshima and Nagasaki.