Analysis: Suspend your disbelief at this point - but the outing of Stakeknife underlines the irony that agents working for the British state engaged in the very illegality they were supposed to be trying to stop, writes Dan Keenan, Northern News Editor.
There appears to be an unwritten rule in Northern Ireland that the bigger and more incredible the controversy, the more muted the outcry.
And so it is that when a well-paid British army undercover agent is publicly named and identified as a feared IRA interrogator, torturer and killer there is little from the many political sources who rush to comment on just about everything else.
The identification of Stakeknife is little short of a disaster for the British army in Northern Ireland and, by implication, for the political establishment in London.
Reports and briefings based on Stakeknife's intelligence probably made it to Downing Street and may have been central to the SAS operation in Gibraltar in which three IRA members were shot dead.
What is also probable is that the source of this reliable high-grade intelligence was indeed the head of the Provisionals' so-called Nutting Squad, which dealt so ruthlessly with suspected informers.
Stakeknife was a key British weapon used against the IRA for between 20 and 30 years. But in order to fulfil that role, he had to become more Provo than the Provos themselves. To protect his identity and the flow of his intelligence to his handlers, he was given a free run. This, it is thought, explains his implication in dozens of murders.
In doing so, this controversy highlights one of the great riddles of "running" double agents or spies - when and how to halt planned paramilitary operations when doing so could expose the source of the intelligence.
It was a question that the Force Research Unit (FRU), the army's equivalent of RUC Special Branch, clearly failed to answer.
To explain this failure, it's useful to re-examine comments made by Sir John Stevens when he forwarded his report on security force collusion to the police in Belfast.
"You have to remember that in 1989 there was a very loose control. . .of what happened with intelligence from the \ army from RUC special branch and other sources. Very loose control indeed," he said.
By this he meant that intelligence agencies in Belfast had lost sight of the point of intelligence-gathering. The objective had become so obscured that completing the intelligence picture became the point of the exercise - not the assistance of detectives working on murder cases. Retaining intelligence was common, sharing it with others was not.
Stevens referred to the effect such secrecy had on crime branch. He continued: "A lot of the intelligence, a lot of the evidence, was held by special branch in particular and also by the FRU. \ was just not made available to them [crime branch]. Therefore, on a lot of occasions, they were in the dark as to what had taken place."
Stevens could remain a key player in this latest twist in the "dirty war" controversy. He was the one to finger Brian Nelson, the senior UDA mole linked to many assassinations, including that of Pat Finucane. Stevens could also finger Stakeknife.
Stakeknife's identification could prove devastating for the IRA now that it has been seen to have been so badly compromised for so long. But it is especially damaging for the British army.
It shows that the British army can't protect its spies and casts doubt, to say the least, over the judgment of those who "run" agents.
It also means that in the unlikely event of a resurgent IRA campaign, the intelligence cover is holed.
The supposed golden rule that informers should not commit crimes while they are in the business of exposing criminals has been shown to be a cruel sham.
The naming of Stakeknife will also prompt questions about the fundamental value of agents. If this spy was so central, then why was the IRA able to function for so long in the manner it did? Then there are the political questions. How will this affect Sinn Féin and - by implication - the stalled political process?
As for the question of transferring policing and justice powers to a restored Assembly, this astonishing revelation could make that issue yet more hypothetical.