Mordecai Vanunu works as a technician inside a secret Israeli nuclear facility built in the desert with Western help, and decides to tell the world what he has seen. The film follows his approach to the Sunday Times in September 1986, when he hands over photographs and details of a bomb-making operation his own government has never acknowledged. British intelligence and Israeli officials scramble once the story is about to run, and Vanunu is given protective assurances that collapse when Mossad agents lure him out of hiding and smuggle him back to Israel, where he is tried and convicted of treason. The episode sits within a five-part series tracing the nuclear arms race from the first atomic bomb through the Cuban missile crisis to the spread of weapons in the Middle East, and treats Vanunu's case as the point where nuclear secrecy runs directly into one man's decision to break it. His conviction, and the operation used to secure it, closes the episode.