The arrival of Tony Blair at Hillsborough Castle last night has opened up the prospect of a deal, with the usual caveat that there is no such thing as a sure bet in terms of the Northern peace process.
Mr Blair met David Trimble in Westminster in the afternoon. Among his scheduled visitors at Hillsborough last night were Seamus Mallon and Gerry Adams. Jim Steinberg, President Clinton's security adviser, was maintaining a watching brief. Further meetings are scheduled for this morning. The British Prime Minister is said to be in "serious arm-twisting mood".
London and Dublin are cautioning against any over-optimism but equally they are saying this is a real opportunity for progress. "This is a serious push," said a London source. One informed nationalist agreed. "This has never been more serious," he said. Notwithstanding some cynicism in the British press that Mr Blair was returning to Northern Ireland to avoid the Commons vote on the fox-hunting Bill, key Northern politicians believe he isn't here empty-handed.
If there is to be a new all-embracing deal, it must involve movement on demilitarisation, genuine IRA engagement with Gen John de Chastelain, policing and the lifting of the Ulster Unionist ban on Sinn Fein ministers attending North-South Ministerial Council meetings.
The difficulty is "who will jump first?" Peter Mandelson did a test leap for his leader in Larne yesterday. Let's stop applying Elastoplast to the problem and solve it once and for all, he said. He strongly signalled that the British government would take an initiative on the British army observation towers in south Armagh - but based on assurances that the IRA would reciprocate meaningfully.
It could be a case of gradual demilitarisation and the gradual diminishing of the IRA arms threat and capability. This would provide some relief for Mr Trimble who is facing the toughest electoral pressure, although he would prefer firmer assurance on IRA arms.
The Westminster election is expected in early summer and if he is to have a real chance of withstanding the onslaught from the DUP - not to mention his internal "No" opponents - he must be able to cite the advantages for unionism of the Belfast Agreement. The alternative could be further suspension of the Assembly and Executive.
If the SDLP endorses the police reform proposals, Mr Trimble will argue that the majority nationalist party has essentially copper-fastened the Northern state. Nationalists will put a different argument, but that's politics and that's how Mr Trimble will play it.
The SDLP in recent days has been teetering on the brink of endorsing the Police Act. It has a list of demands on matters such as the Special Branch, police symbols, Gough Barracks etc, which have been conceded in principle.
Its central demand has been for independent inquiries into the killings of Pat Finucane, Rosemary Nelson and Robert Hamill, which Mr Mandelson has been resisting, while indicating some room for manoeuvre. SDLP sources said it was significant that among its delegation at Hillsborough last night was Agriculture Minister Brid Rodgers, in whose constituency Ms Nelson and Mr Hamill lived.
Sinn Fein, however, continues to complain that the British government has destroyed Patten. How to bring it into the policing equation, or whether it is prepared to sign up to some deal which doesn't fully meet its requirements on policing, remains a difficult question.
There are lots of uncertainties and no guarantees for the parties. "There are risks involved in this for everyone, but the greater risk may be to do nothing," said one senior talks source last night. His hope was that the imperative for movement would ensure that the key pro-agreement players would engage in mutual risk-taking.
The Taoiseach, Mr Ahern, is ready to travel to Northern Ireland at short notice. It is understood that Mr Blair must return to London at lunchtime.
There's also talk of Mr Blair and Mr Ahern going to Hills borough tomorrow if a deal can be completed, or possibly returning for a final bout of persuasive talking next week.
The British-Irish Council meeting in Dublin on Tuesday is another opportunity for serious talking, but with the Westminster election approaching, time is severely limited.