Watch The Troubles: A Secret History Season 1 Episode 5 Online

Unionist anger grew as IRA attacks on the security forces killed members of their community. When Margaret Thatcher signed the Anglo-Irish Agreement in 1985, giving the Republic of Ireland political influence in the North, the anger spilled over leading to loyalist groups rearming. Using intelligence leaks to boost their campaign of killing, new information reveals MI5 agents operating inside the largest loyalist group, the Ulster Defence Association.