Few people in Britain or Ireland strike as much fear and terror into the hearts of others as Johnny "Mad Dog" Adair. The Ulster loyalist paramilitary godfather now lives in exile in Scotland following a murderous feud with his own people. Over a 20-year reign, his organisation - the notorious Ulster Freedom Fighters "C-Company" - is thought to have committed over 40 murders and attempted hundreds of others. Adair's main conviction is one of Directing Terrorism, for which he was sentenced to 16 years in prison. In 2006, reporter Donal MacIntyre spent several months with Adair filming a powerful full-access documentary with one of the nation's most feared figures. It's a journey that takes MacIntyre into the heart of Adair's new Scottish empire, among his neo-Nazi supporters in Germany, and a high risk foray to Belfast where Adair faces continuing death threats. The film also reveals Johnny "Mad Dog" Adair's adoring fans, including self styled lottery lout Mickey Carroll who was recently jailed for an assault on a group of young Christians at a gospel concert. Most controversially, Adair comes face to face with the man who brought him down: Detective Sergeant Johnston "Jonty" Brown. MacIntyre's Underworld: Mad Dog offers unique access into the mind of a terrorist leader. It also asks what's next for one of the country's most dangerous men.