In the early 1970s, Sir Maurice Oldfield of the British Secret Service, MI6, embarked upon a decade-long campaign to derail the political career of Charles Haughey. The English spymaster believed Haughey was a Provisional IRA godfather, therefore, a threat to Britain. Oldfield was assisted by unscrupulous British agents and by a shadowy group of conspirators inside the Irish state's security apparatus, all sharing his distrust of Haughey.

Escaping scrutiny for their actions until now, Enemy of the Crown examines more than a dozen instances of their activities. Oldfield was conspiratorial by nature and lacked a moral compass. Involved in regime change plots and torture in the Middle East, in the Republic of Ireland he engaged with convicted criminals as agent provocateurs as well as the exploitation of pedophile rings in Northern Ireland.

He and his spies engaged in dirty tricks as they ran vicious smear campaigns in Ireland, Britain and the US. MI6 and IRD intrigues were deployed to impede Haughey's bid to secure a position on Fianna Fail's front bench and any return to respectability. London's hateful drive against Haughey saw no let-up after Fianna Fail's triumphal return to power in 1977 which saw them win a large majority of seats in the Dail.

When Haughey sought a place at Cabinet, Oldfield and his spies devised more dirty tricks to impede him. While Haughey was suspicious of MI6 interference, he had no inkling of the full extent of London's clandestine efforts to destroy him. By circulating lurid stories about him, they played a major part in trying to prevent him succeed Jack Lynch as Taoiseach in 1979.