In 1942 Norwegian Odd Nansen was arrested by the Nazis, and he spent the remainder of World War II in concentration camps--Grini in Oslo, Veidal above the Arctic Circle, and Sachsenhausen in Germany. For three and a half years, Nansen kept a secret diary on tissue-paper-thin pages later smuggled out by various means, including inside the prisoners' hollowed-out breadboards.

Unlike writers of retrospective Holocaust memoirs, Nansen recorded the mundane and horrific details of camp life as they happened, "from day to day." With an unsparing eye, Nansen described the casual brutality and...