In May 1973 a group of scientists, physicians, and dignitaries gathered in the lobby of a Hiroshima research institute to open several large wooden boxes. Shipped a few days earlier from the United States, these boxes contained twenty-three thousand items, including photographs, autopsy records, clothing, and four thousand pieces of human remains. The institute director later appeared in a newspaper photograph holding up several plastic bags filled with wet tissue —hearts, lungs, livers, eyes, and brains, immersed in formalin and doubly sealed, whole organs marked by the radiation produced by the atomic bombs in August 1945.1 These body parts spent twenty-eight years as state secrets in an atomic boom-proofed building in Washington, D.C. T...