It was shortly after 7.20 p.m. on Friday that word spread among the tired politicians and officials from the two governments and the North's political parties at Hillsborough Castle that something very significant had just happened.
For over a month, the talks had been stalled on the basic issue of trust. Both the Ulster Unionists and the republican movement were willing to settle for less than their public stated positions, but neither would announce a climb down unless they knew they could trust the other side to climb down too.
Thus the UUP leader, Mr David Trimble, had made clear in Washington on St Patrick's Day that he would be willing to try to lead his party back into the political institutions on the basis of a "sequence" of events and statements that stopped short of providing IRA weapons "up front". However, in the absence of any IRA offer, he refused to set out what precisely he would be willing to accept.
In response, Sinn Fein had worked out, in consultation with the two governments and the IRA, the text of a statement the IRA could issue as part of such a sequence in an effort to bring about the restoration of the suspended political institutions.
But again, this remained a hypothetical position, metaphorically placed on a shelf rather than on the table. Neither side was going to announce a weakening of its position unless it knew that this would be enough to bring a weakening of the other's stance.
The republican movement was determined, after its 11th-hour visit to Gen John de Chastelain on February 11th failed to avert suspension of the political institutions, that it would be making no further offers until it knew they would be accepted.
The Ulster Unionist Party position was the mirror image of this: it would not give details of a weakening of its demands of the IRA - thus giving further ammunition to unionist rejectionists - until it knew the IRA was willing to agree to concede this new minimum position.
However, despite the hypothetical nature of each side's position, substantial work was done on refining and strengthening the potential IRA statement.
About two weeks ago, the proposed wording was in a form believed capable of extracting a positive response from the UUP. The idea of opening up IRA weapons dumps for inspection has been in various proposals for over a year. Now this idea was hardened and refined through exhaustive contacts between officials and Sinn Fein.
For close to a year, there has been a proposal favoured in nationalist circles that members of the Catholic hierarchy would play a key role in any process to deal with weapons.
About a fortnight ago this was dropped in favour of the formula which instead sees former Finnish president Mr Martti Ahtisaari and former ANC secretary-general Mr Cyril Ramaphosa taking a role as independent third parties.
Further minor changes to the document were made during seven hours of talks at Downing Street last Tuesday, and again on Wednesday and Thursday.
And there the IRA statement remained on Friday at Hillsborough, ready but on the shelf, as at 6.30 p.m. the Ulster Unionist Party and Sinn Fein leaderships went into their first detailed meeting since the political institutions were controversially suspended on February 11th.
During the next 50 minutes, the UUP and Sinn Fein made the crucial leap to trusting each other: Mr Trimble indicated he would view the IRA offer positively, and the IRA indicated it would make the offer.
As that meeting broke up at 7.20 p.m., word spread inside the building very quickly that the weapons issue, which has dogged the process for over five years, now appeared close to resolution.
Officials and politicians from the two governments and the different political parties came out of their rooms and held informal, excited discussions in corridors, doorways and the gardens of Hillsborough Castle.
But it wasn't over and suddenly there was talk of continuing into the night, maybe even resuming the following day, Saturday. Now the problem was not decommissioning, it was police reform.
Mr Trimble and his party had been pressing hard all week for some concession on the implementation of the Patten report's recommended reforms of policing. After the meeting with Sinn Fein was over, Mr Trimble was back with Mr Tony Blair, pressing his demand for something to increase his chances of getting the new deal on decommissioning past his party's ruling Ulster Unionist Council.
The previous Ulster Unionist Council meeting in February had passed a motion proposed by Mr David Burnside that linked future UUP participation in the political institutions with the retention of the name of the RUC and its badge, incorporating a crown on top of a harp.
Mr Trimble was now being asked to go back to the Ulster Unionist Council and persuade his party to re-enter the political institutions without any concession on Patten.
The two governments recognised Mr Trimble had a serious problem and for the next three hours discussed various possible concessions that could be given.
Suggestions that the RUC name be incorporated into or hyphenated on to the new Northern Ireland Police Service title were rejected after members of the SDLP delegation produced a copy of the 1998 legislation on policing.
That legislation states that the name of the police force is the Northern Ireland Police Service, adding that it incorporates the RUC and the RUC reserve.
The SDLP delegation pointed out that the police force was nevertheless known to all as the RUC, and would continue to be so known unless the RUC name was dropped altogether.
Discussion of the RUC badge centred on whether the crown symbol could be retained in the force's new symbol. Again there were strong nationalist objections.
After three hours, the two governments said they would not continue discussing Patten at that stage, and would in fact announce immediately what had been achieved. They would write to all party leaders the next morning outlining plans for the implementation of the remainder of the Belfast Agreement. They expected the IRA statement to be made public shortly, and proposed to reinstate the political institutions on May 22nd, presuming all parties responded as required.
They acknowledged the UUP had a problem on the policing issue and agreed to talk further about it this week.
"There is scope for something," says a Government source. "There may be some way to recognise the role of the RUC while getting rid of the name. Nobody has actually figured it out yet."