It's difficult to credit now how significant the murder of Kevin McGuigan was. It provoked a political crisis that threatened the whole devolution project but since then the institutions have recovered and fallen again.
McGuigan was cut down outside his home by an armed gang which moved quickly and efficiently.
He was killed to avenge the murder of 'Jock' Davison. That had been a more opportunistic hit and many republicans held him to blame for it.
The first murder had not roused strong suspicions of Provisional IRA involvement. Indeed, senior Provisionals were quickly on the scene commiserating with his stricken and outraged family.
But the police said that some members of the IRA were involved in the murder of McGuigan and that statement triggered a crisis.
One fear was that the Provos had broken their ceasefire and ordered an execution.
The more reassuring theory - if there can be reassurance in such an event - lay in the suggestion that the killing had not been ordered by the IRA command.
This was the formula by which the peace process had been saved before, from its earliest days. A murder was defined as 'unsanctioned' and therefore not as a breach of a ceasefire.
In reality, proving that a murder had been sanctioned was almost impossible.
The political recoil was led by then Ulster Unionist leader Mike Nesbitt withdrawing his party from the Executive.
When Bobby Storey, a former IRA prisoner with a senior role in Sinn Fein, was arrested on suspicion of involvement in the murder the panic spread to the DUP.
Peter Robinson announced that his ministers would resign serially.
That is, they would give a week's notice, leave their jobs, turn up for a day to 'unresign' and then give another week's notice.
It was a creative device for stalling the work of the Assembly without bringing it down.
One minister was left in post - Arlene Foster at Finance - to mind the coffers.
The way out of this crisis, as before, was an intensive talks process accompanied by a report on the security situation to inform the parties on the real status of the IRA ceasefire.
The report said that the IRA was not militarily active, had redirected its energies into politics, but that many in the IRA still believed that the army council controlled Sinn Fein.
Storey had been released after some hours under interrogation. He gave a Press conference in which he said that the IRA was like a butterfly that had flown away.
Sinn Fein was similarly delicate in its choice of words, repeatedly declining to say that the Provisional IRA had been disbanded, preferring phrases like "left the scene".
But there was more to the deadlock between the DUP and Sinn Fein.
There was also a dispute about how to implement welfare cuts and mitigate against their effects.
And progress with that issue seemed to eclipse concerns about the Provisionals.
Sinn Fein made a statement that it was not controlled by anyone, committed itself against paramilitary influence, and we then had the Fresh Start Agreement by which devolution could continue.
Except that it hasn't.