Franz Stangl was the Nazi commandant of the Treblinka and Sobibor death camps in Poland. He was responsible for the extermination of around 900,000 men, women and children. At the end of the war, he escaped to Italy where he joined a "rat-line" organised by Vatican officials. From there, he disappeared. Simon Wiesenthal was a survivor of the Holocaust. Born in the Ukraine in 1908, he was rounded up with his family in 1939 and imprisoned in a labour camp where he serviced the German railroad. In May 1945, he was liberated by Allied soldiers from Mauthausen camp. His six-foot-frame weighed barely 99 pounds. Restored to health, he vowed to track down some of the Nazi monsters who had put him and so many other Jews through hell.