Some of those involved spoke of glimmers of hope and a sense that movement was possible from both the republicans and the Unionists who have for so many months been locked in the impasse overarms decommissioning.
They did not, however, predict any early or easy breakthrough that might satisfy both constituencies, and there was mystery about an early-afternoon report that said a settlement was on the cards.
The sense of optimism fluctuated throughout the day, with some high morning hopes dimming as the afternoon wore on. At the same time, there was a growing sense that all sides were engaged in a serious search for a settlement of the long-running issue.
Publicly, though, republicans and Unionists gave no overt inklings of major changes in their positions, the former saying the IRA was not about to give up weapons, while the latter maintained that no new executive would be formed if they did not.
One of the most upbeat assessments came from the Irish Foreign Minister, David Andrews, who said: "Altogether the atmosphere is one of friendliness and a wish for a solution to this terribly, terribly difficult problem. We have succeeded in getting this far by finding solutions with which all sides can live. I think we have to do the same thing with the present impasse, and we don't have very much time to do it."
Mr Blair and Mr Ahern were heckled by loyalists as they made their way to the large helicopter parked, symbolically, on the lawn right in front of Stormont.
A couple of republicans engaged in their own version of agitprop, meanwhile, by climbing the large statue of the Unionist hero Sir Edward Carson, which dominates the Stormont grounds, and hoisting a tricolour. A furious Ian Paisley demanded that police take them away, and they eventually climbed down.
In the afternoon, the action moved from Stormont to the baronial splendour of Hillsborough Castle in Co Down, where the two prime ministers held talks centring on the Ulster Unionist party leader, David Trimble, the Sinn Fein president, Gerry Adams, and the SDLP leader, John Hume.
A senior official at the Northern Ireland Office said: "They are not wasting their time. Therefore there must be some movement, but it remains difficult. There are glimmers of hope. Equally there is a lot of hard work to be done, but there are no guarantees. There is still a big gap to be closed."
In addition to the straight political meetings, Mr Blair held several meetings with representatives of Portadown's Garvaghy Road residents and leaders of the Orange Order who have been involved in the Drumcree marching stand-off.
Mr Trimble said: "We are conscious of the historic opportunities that exist here. The question is whether the paramilitary parties have the will to grasp this historic opportunity to implement this agreement in its entirety.
"The choice lies with those who have yet to carry out their side of the bargain. We have done all we can do."
In a symbolic visit to a religiously integrated school in north Belfast, Mr Blair declared: "I will not stop or rest until this thing is done. Without trust between the parties, this Agreement isn't going to work, but I believe we can get there."
Sinn Fein's chairman, Mitchel McLaughlin, said he was encouraged everybody was working collectively to resolve the impasse. "I have noticed spokespersons talking in terms of the `D' [decommissioning] word as an issue which will be resolved by voluntary action - a much more pragmatic and sensible approach - and I would hope that all of the parties can get behind that kind of common sense and systemic addressing of the problems."
Anne McElvoy, Review, page 3Reuse content