In April 1975, Simon Wiesenthal, the Holocaust survivor whose efforts to track down Nazi war criminals had earned him the title of “Nazi hunter”, wrote a letter to Albert Speer, the Nazi war criminal. Wiesenthal thanked him for a psychology book Speer had sent him, and forwarded a copy of the French edition of his own memoir. Their decade-long correspondence also includes holiday postcards and birthday wishes. It ends with a personal note from Speer’s widow Margarete on her husband’s death in 1981, telling Wiesenthal how important their friendship had been to him. Wiesenthal’s friendship was a private echo of...