Idriss Gabel and Marie Calvas are the grandson and granddaughter of Rudolf Hess's last chaplain in Berlin-Spandau prison. Hess (1894-1987), a fanatical anti-Semite, was Adolf Hitler's deputy in Nazi Germany and personally participated in the formulation of the Nuremberg Race Laws. As a French military chaplain, Charles Gabel was the only person authorized to speak with Hess in private for almost ten years. In this documentary, his grandchildren ask: What kind of relationship did their grandfather have with this member of the Nazi leadership? Hess was sentenced to life imprisonment in 1946 as part of the Nuremberg Trials of major war criminals. He served his sentence throughout the Cold War as the sole inmate of the huge Spandau Prison. In 1987, at the age of 93, he took his own life.