For years the letter lay in a box in the attic. It was postmarked in April 1945, just before the Nazis’ surrender in World War II. It was just one letter among many letters, and the box was just one box among many boxes.
“Yesterday we visited something that you might have already read about in the newspaper or heard about over the radio,” the letter began. “Not very far from here there is a concentration camp.” Another letter, dated 13 days later, added a detail: “The name of the camp is Buchenwald located near Weimar here in Germany.”