In this episode, the story comes up to date with the 20th century. Starting at Munich's beer halls, we learn about Hitler's first revolt at the Munich Putsch which resulted in his imprisonment at Landsberg, where the young Hitler was to dictate his memoirs, Mein Kampf. Whilst Hitler was fighting for power in Germany, women were fighting a different battle, that of sexual rights. In the back streets of Manhattan, nurse Margaret Sanger works with American heiress Katherine McCormick in a plan to smuggle contraceptives into America from Europe. At the Babi Yar concentration camp outside Kiev, we find out about the brutal mass murder of the Jews by the Nazis across Europe. The episode also travels to Hiroshima in Japan, the site of the world's first atomic bomb by Oppenheimer, thought to end all wars. In China, we learn about how new thinking came in Mao's Cultural Revolution, in trying to create a communist utopia. We visit New York to trace the story of man versus machine, Gary Kasparov against IBM's Deep Blue, in a chess game that gripped the world. The series ends with a 360 degree turn, finishing with the Ayoreo tribe in the Chaco region of South America, a tribe who had only recently made their first contact with the outside world.