The Stakeknife case will focus on a series of IRA killings and what was known inside the intelligence agencies - military, Special Branch and MI5.
Stakeknife was an agent codename, described as the Army's “golden egg” operating inside the IRA; not just the IRA, but at the heart of its internal security.
And we know the role and purpose of IRA internal security - the interrogation of suspected informers often leading to executions with bodies dumped at the roadside or on country lanes.
Think about it. One agent interrogating other agents.
Precisely how many killings are to be investigated is still not clear. It could be dozens.
Belfast republican Freddie Scappaticci fled Belfast in 2003 denying he was the agent Stakeknife.
That denial was dismissed by others.
In a brief interview at the time, he told me he did not know why the label Stakeknife had been attached to him.
He did not deny being part of the republican movement – adding: “But I have no involvement this past 13 years.”
That meant since 1990. Others believe his “involvement” with the IRA stretches beyond then.
Now, we wait for the details of the latest investigation.