Everything about the IRA murder of Caroline Moreland is horrific, but some elements are bizarre. The confession that she recorded included an appeal to other police informants to break cover and get themselves off the hook. This was a fairly standard statement issued by several people at the time who were trying to evade recruitment.
A common example was that someone would be coaxed into accepting a small sum of money and a telephone number for a handler. One man I spoke to had £30 in a cigarette packet thrown to him from an Army vehicle.
Those who feared they were in the early stages of being recruited as 'touts' would often go to a solicitor and issue a statement to the media, or even hold a Press conference.
And they would use a form of words similar to that used by Caroline Moreland, acting in the faith that they would be spared.
Caroline clearly believed, when she recorded that part of her statement, that she would not be killed. Otherwise she was just tempting others in her predicament into a process that meant certain death.
So the IRA wanted informers to believe that there was a possible escape route through honest disclosure.
One of the most chilling things said by Freddie Scappaticci in a conversation surreptitiously recorded in the car park of the Culloden Hotel in 1993, a year before Caroline's murder, admits to the deception.
He said: "They think they are going to go home, but they don't."
But her sense that she was in the clear is still puzzling. Possibly, her interrogators were tricking her into thinking that she would go free, but then there was little value in recording that statement. No one was going to believe her appeal to others if she was already dead by the time they heard it.
That logic raises the suspicion that her interrogators didn't expect to have to kill her and were overruled, probably at one of those Tuesday meetings of northern command in Belfast.
Scappaticci said that he was no longer on the northern command in 1993 and that Martin McGuinness had stepped back from it, too, to join Adams in political work.
One scenario - that she was deceived into thinking she would go free - depicts her interrogators as brutally cynical. The other - that she had a realistic expectation of going free, but that the prospect of sparing her was revoked - suggests pragmatic political thinking.
One suggestion, voiced on Facebook, is that the IRA killed her on the virtual eve of a ceasefire because sparing her would make them look as if they were going soft. Who knows?
What we do know is that two other players in the dirty war had a hand in what was happening.
One was the Army's Force Research Unit (FRU), which ran Freddie Scappaticci as an agent. It had also been running Brian Nelson inside the UDA. Another was RUC Special Branch, which had turned Caroline Moreland.
We don't know what their objectives were in relation to her; whether they cared to save her, or not.
And so much information has now come out about the ways in which these bodies handled agents, fed them with intelligence and looked the other way while those agents committed murders, that someone really has to come forward and explain their brutal behaviour.
Yet all we get is plummy generals making glib, superficial statements and otherwise evading the media and the law.
We do know that the Army and police didn't get on. The FRU may well have known that Caroline Moreland was about to be questioned and executed by the IRA. They did nothing to intervene.
They made no attempt that we know of to warn her.
Did they even warn Special Branch that one of its recent recruits had been exposed? We don't know. We do know, from the de Silva report into the murder of Pat Finucane that FRU and Special Branch often hid information from each other.
When the FRU agent inside the UDA, Brian Nelson, disclosed a plan to kill Gerry Adams in 1987 by planting a limpet mine on his black taxi, they did not trust the RUC to scupper the attack, so they took on that job themselves. We know that the Army was highly averse to allowing Adams to be killed by an agent, because he was an elected representative. Still, it fed mountains of information on other republicans to the loyalists through Nelson.
The excuse made to de Silva was that targeting senior republicans would spare innocent Catholics and absorb loyalist energies and then make it easier for the Army to intercept attacks, because they would know who the intended targets were. But they often didn't even ask their agent Nelson whose details he had passed on.
RUC Special Branch learnt that the UDA was planning to raid the armoury of the UDR in Coleraine. The Army was quite miffed when this raid went ahead without it being told to expect it and prepare.
This lack of co-operation between the Army and the police is a possible part-explanation for why Caroline Moreland's murder went ahead.
And there are many other sinister theories out there, too.
Some speculate that Scappaticci's job for the Army was simply to kill low-grade touts, to boost his credibility within the IRA and thereby justify his seat on the northern command and his access to McGuinness, the real prize.
One might even wonder if the prolific efforts to recruit low-level informers had any value other than to provide fodder for the 'nutting squad', the way live mice are fed to a trained falcon.
There are unanswered questions now which open up the space for the most damning speculation about the activities of the FRU and Special Branch. And no one comes forward to justify, or explain, perhaps because no viable justification exists.
De Silva found that the Army and the police agent-handlers were acting without proper legal guidelines.
The law said you couldn't ask an agent to do something illegal. Membership of the IRA was illegal, so just running an agent in any role inside the IRA - even making the tea - was, arguably, illegal.
But the Government rejected pleas to change the law and provide solid guidelines for agent-handling.
And that was because the dirty ways of working were getting results and top agents were sitting down with Gerry Adams and Martin McGuinness, and the IRA had virtually no secrets any more. They were not going to jeopardise that.