S1, E2: In 1943, the Allies launched a campaign to liberate Italy from the grip of the occupying Nazi forces. The key to their success: the capture of Rome, but strong German resistance and tough terrain turned what was supposed to be a five-week mission into a nearly year-long conflict. Now, military experts are using the latest drone imaging technology to understand how the Nazis used the Italian landscape to their advantage and to discover more about what happened at Monte Cassino monastery, the site of one of WWII's most controversial bombings.