Sinn Fein and the UUP remain poles apart on sanctions and IRA decommissioning, writss Gerry Moriarity, Northern Editor
Hillsborough Castle was a fever of activity throughout yesterday: officials and politicians discussing policing in a room here; the mechanics of demilitarisation in a room there; a bill of rights in another; "on the runs" in some other quiet little corner of the Northern Secretary's residence.
And then there was the issue of sanctions and whether IRA decommissioning would be in secret or given the Steven Spielberg "lights, camera, action" treatment.
At the time of writing last night, these were the two great unresolvables. Sinn Féin and the Ulster Unionists were on opposite sides of the castle on these issues.
But there was progress otherwise. A 28-page package dealing with all the issues, with five annexes, prepared under the gaze of the Taoiseach, Mr Ahern, and British Prime Minister, Mr Tony Blair, was shown to the parties.
Up to last night that was the two leaders best read on a deal. They are re-engaging with the parties in very serious, very focused horse-trading at Hillsborough again today.
"We are more than 90 per cent there," said one official last night.
The fact that Mr Blair, in particular, with war and peace on his mind - the former in Iraq, the latter in Northern Ireland - was overnighting in Hillsborough indicated a deadly seriousness about talking the parties into submission and agreement.
Outside the castle yesterday, we had press conferences, spinning, chit-chat and reporters shooting the breeze.
The two governments believed it was close but politicians and pundits alike couldn't get an absolute fix on whether the main disputing sides, Sinn Féin and the UUP, would meet in the middle.
Then around lunchtime, as the SDLP was giving a press conference, a car snuck up to the entrance gate. In the passenger seat was an unassuming-looking octogenarian with distinctive large glasses, Joe Cahill, icon for all the living generations of current and former IRA members.
It seemed propitious, a symbolic but important gesture, a former IRA chief of staff entering Hillsborough Castle ready to issue his stamp of approval should a deal be on the cards.
There was a lot of talk of verification yesterday: here was the republican movement's lone verification commission.
Unionists have consistently questioned republicans' commitment to strike agreement and restore devolution.
Were they in for the long or short game, i.e. would they fall short in what they might deliver or would they be sufficiently radical to reassure unionists they were genuine?
"We always play the long game and that is about getting the Brits out of Ireland," said Mr Gerry Adams's spokesman.
So, not much chance of a deal then? Not so, he said.
"We are not playing the long game in terms of getting a deal here, because that risks seeing the whole edifice of the Good Friday Agreement crumbling, and that would be enormously dangerous.
"We are here to get a deal, if not today then tomorrow. If not tomorrow, then next week, but we are here to get a deal," the spokesman added.
That didn't tell us how the IRA would demonstrate that it was a superannuated force, but it was an emphatic declaration nonetheless that republicans wanted to end the perpetual round of political crises afflicting the process.
Or, as SDLP leader Mr Mark Durkan described it, this "Homer Simpson nightmare".
There was a real buzz of anticipation at Hillsborough yesterday, a sense of tension and expectation not experienced since the week leading to the Belfast Agreement five years ago.
But mood doesn't necessarily metamorphose into resolution as Mr Blair and Mr Ahern know very well from many late nights and long association with this process.
Much of the package was already in the can: toppling the south Armagh watchtowers; devolving responsibility for criminal justice and policing to the Northern Executive; guaranteed freedom for IRA members still on the lam; money for the Irish language; commitments on a bill of rights; support for victims and a verification commission to ensure that all the participants were maintaining their side of the bargain.
In return, the IRA was expected to terminate all activity and carry out major act or acts of decommissioning and Sinn Féin was expected to join the Policing Board - one of the surest signals that the IRA's war is over.
All of this seemed perfectly realisable but problems arose when the negotiators worked their way through the undergrowth of the package in waiting.
Mr Trimble was insistent that anyone - read, the IRA - in breach of commitments must face graduated sanctions - a sort of peace process "penalty points system", to quote Mr Durkan again.
Not in the agreement, according to Sinn Féin's Mr Mitchel McLaughlin.
Mr Trimble, in grave read-my-lips mode, said sanctions could be a "deal breaker". He said there must be open, transparent decommissioning which would involve cameras and witnesses additional to the International Independent Commission on Decommissioning.
Out of the question, said Mr McLaughlin, if Mr Trimble couldn't trust Gen John de Chastelain and his colleagues then he couldn't trust anybody.
Both sides are hardballing on these issues. However, Mr Ahern and Mr Blair, together with their officials and the other politicians, seemed to believe that middle ground could be found on these matters.
That's why they decided to return today.