After two close calls with lone-wolf assassins, a string of failed plots by foreign governments, and ineffective resistance movements, Hitler’s security tightens significantly. He withdraws from public life and begins spending most of his time at the Wolfsschanze (The Wolf’s Lair). As a result, only his military officers have access to him, meaning that any future attempt on Hitler’s life will have to come from within. Watch Killing Hitler, Wednesdays at 8pm, on National Geographic UK | National

Watch: Can a lone wolf chase down a much larger—and faster—caribou? | National Geographic