The European Union has been waiting patiently to see what kind of prime minister Liz Truss will turn out to be when it comes to the Northern Ireland Protocol: a pragmatist or a hardliner.
The death of Britain's Queen Elizabeth has suffused expectations with both foreboding and hope.
"It is a moment of incredible introspection in the UK," says one London source close to the Conservative Party. "It's difficult to overstate the feeling of a sense of rudderlessness."
One well-placed Brussels source says: "There's a new government, a new king. You could imagine people wondering what impact the queen's death might have. It may have created a window."
The passing of the monarch has certainly impacted the architecture of a reset in EU-UK relations, now that Truss has become prime minister.
On Wednesday 7 September, the day before the queen's death, European Commission President Ursula von der Leyen told EU ambassadors over lunch that Team Truss had been in touch and wanted to set up a phone call.
"The call never happened," says an EU diplomat. "If they do meet, it may now be on the margins of the funeral."
Ms Truss did speak to Taoiseach Micheál Martin, the call dominated by the queen's death, her visit to Ireland in 2011 and how much that contributed to the reconciliation process.
"There were vague references to the need to discuss and clear up the issues at stake," says one source briefed on the call. "Truss said she'd like to meet the Taoiseach in London if he attended the funeral."
According to another source: "She said to the Taoiseach her preference was for a negotiated settlement.
She was certainly encouraging him to believe there's sincerity in that, and I don’t doubt it."
The European Commission took a deliberately understated approach to a potential flash point this week.
Thursday was the first deadline for London to respond to EU legal action over non-compliance with the Protocol.
"It will be very low key this week," said one EU source on the eve of the deadline. "No fireworks."
The legal action dates back to March 2021 in response to the UK unilaterally extending the grace period for animal products to require export health certificates (EHCs).
That action was frozen to allow both sides to get into talks last autumn on easing the burden of the Protocol, but it was unfrozen in June when Truss introduced the Protocol Bill.
The European Commission followed up with two more infringement proceedings in June, and a further four in July.
The UK's written response arrived on Thursday morning, right on deadline. "We will now analyse the reply before deciding upon next steps," said Commission spokesperson Dan Ferrie.
The Commission will calibrate those next steps depending on whether Truss engages with the EU's offer of further flexibilities (first published last October), or plows ahead and passes the Northern Ireland Protocol Bill, which effectively dismantles the Protocol.
The Commission is expected to take its time in analysing the UK letter. While diplomats believe it will fall short in justifying the UK's non-compliance, the Commission will not rush the case to the European Court of Justice, which would be the normal course of action.
"My expectation is that whatever is in the UK letter would not be enough to avert [court action], judging by the way this has been handled so far - unless the UK has launched a grand overture," says another EU diplomat.
"But if we’re talking about a reset, we would very much support that and the Commission would as well. Therefore you could possibly see the Commission looking for ways to provide space for that reset to either happen or at least be explored before they push for the court."
However, the Commission will keep the threat of court action on the table.
"We're entirely in control of the calendar," says one source. "So, we can hold on, we can ask [questions] forever. It's still to be decided upon. But I would imagine we will ultimately want to move on to the next stage: a letter of formal notice, to a reasoned opinion, to a referral to the European Court of Justice."
This is in keeping with the EU's approach to UK recalcitrance on the Protocol: tightening the screws through legal action but avoiding overt escalation (officials have long said this would simply play into the hands of UK hardliners).
Will Truss return to the October proposals of last year?
During her lunch with EU ambassadors, President Von der Leyen said she would tell Truss that the EU would not renegotiate the Protocol and that the solution would have to be found within its framework.
Brussels has certainly been signalling that if the British do engage, then the EU can go further than the October proposals.
"The EU definitely can go further," says one EU source. "This was clear in June when then the Commission expanded on the [October] papers. But stuff was just not discussed because the UK didn't engage, or didn't want to engage."
An EU diplomat says: "If a UK precondition is a renegotiation of the Protocol, that makes it all much more difficult. But if the British are open to resuming negotiations in good faith, and trying to come to a solution-based on the package of last October, but with the Commission indicating they were prepared to go further, then we may be in business."
UK officials have made it clear the October proposals, and even the expanded version of them in June, still do not go far enough. So it is clear a significant gap remains.
The Northern Ireland Protocol Bill is still in the background, and will start its progress through the Lords in October.
While still regarding the Bill as a loaded gun, the European Commission will not demand it be frozen while the talking continues.
"Even if the legislation begins its journey through the House of Lords," says the diplomat, "the Commission is prepared to continue to discuss. But of course, all bets are off if the legislation is passed. Then we're in a different scenario altogether. But up until that point, the Commission's doors are open."
The choice facing Truss, therefore, is whether to go through those doors, all the while reassuring hardliners that the Bill is still making its way, or dig her heels and insist at the outset, as she did in the Commons on 7 September, that unless all the Bill's elements are agreed by the EU (essentially a dismantling of the Protocol) then the UK press ahead with the Bill.
There are optimists and pessimists.
According to one source familiar with Tory backbench sentiment: "Truss believes, like her predecessor, that the EU won't move until they see the glint of bayonets. Once they see the glint of bayonets they will understand that the UK is not joking."
In other words, Truss will press ahead with the Bill unless the Protocol is completely revamped.
"Her message will be," says the source, "I was the foreign secretary, so I understand the importance of international relations and of having a more stable relationship with the EU. But I'm not prepared to compromise on Northern Ireland."
Truss may have made a signal of intent by placing European Research Group (ERG) street fighters at the heart of the Northern Ireland Office (NIO), with Steve Baker appointed as Minister of State and former ERG chair Chris Heaton-Harris as Northern Secretary.
According to one UK source, Truss deliberately made those appointments to strengthen her armory against the EU, alongside the Protocol Bill and the threat of Article 16, which would suspend parts of the Protocol.
According to this view, Truss championed the Protocol Bill because she could only become prime minister with the votes of the ERG, but with such a narrow win within the Parliamentary party she cannot dispense with those hardline eurosceptic MPs.
"This is a government which has been built for fighting," says the source. "It's not even that she necessarily knows the fight that she wants to pick, or wants to pick the fight. It's just that she doesn't have the support within the party not to pick a fight."
Dublin is keeping its counsel for now, noting that on his first day taking Northern Ireland questions in the Commons, Chris Heaton-Harris stuck to a noticeably careful line on preferring a negotiated settlement.
Truss may have made the appointments in order to make sure she had the harder wings of her party on board as she enters the fray, according to one Irish official.
In the meantime, Dublin will want to test Truss's declaration of her preference for negotiations.
"If you will the end," says the official, "you have to be ready to provide the means. And that means, are you ready to do what it would take to get to a negotiated settlement? That's the unknown."
On RTÉ's Morning Ireland programme on Friday, the Minister for Foreign Affairs Simon Coveney was more forthcoming.
"I have some cautious optimism that we will see, in a few weeks time, the opening of an honest effort to try to settle some of these issues…," he said.
"That does require compromise on the UK side as well as the EU side. There is a landing zone if there is a real effort to try and achieve it, and if the teams work on that basis. I hope and I suspect that the British government is up for that and that the British prime minister will instruct her team to move in that direction."
The Taoiseach and Truss meet in Downing Street on Sunday morning, and Truss will meet Ursula von der Leyen at the UN General Assembly during the week.
Meanwhile, the jury is out on how long it could take the Bill to get through the Lords (some say Christmas, others say it could drift into next year).
All the indications are that peers are not going to die in a ditch over the Bill and that Downing Street will not need to invoke the Parliament Act to get around any hold up (Truss can accuse the Lords of endangering the Good Friday Agreement if they delay or heavily amend the Bill).
The prime minister can also decide to speed up or slow down the passage of the Bill, depending on how the talks are going (if and when they get under way).
"If she wants to achieve something [in the negotiations] there's an opportunity to do it," says the Irish official. "There's no advantage for the UK in stringing things along, but if [the EU] feel that things have changed, that they’re now dealing with a serious operation, then there'll be a willingness to meet them."
There's also the issue of the DUP.
The party is under increasing pressure (even in a not so subtle form from King Charles) to return to Stormont.
While the new Secretary of State can always legislate to delay the mandatory Assembly elections that should be called should no executive be formed by 28 October, DUP leader Jeffrey Donaldson may be persuaded to agree a staged return in order to show "good will" (MLAs who have wanted the Assembly formed from the word go will soon have their salaries reduced because of the DUP’s refusal to restore power-sharing).
But Donaldson is under pressure from fundamentalists in his party not to return unless the Bill is enacted and the Protocol replaced.
Yet, there are hints in the recent remarks of Maros Sefcovic, the EU's chief negotiator, about making the sea border "invisible" by whittling down checks to a handful of lorries a day, that might open the door to the DUP softening its position.
"In terms of what comes from the EU, in terms of a silencing of the protocol, in taking out the visibility of the Protocol," says Jon Tonge, Professor of British and Irish Politics at Liverpool University, "I think there are some in the DUP who recognise that that is as far as they can go.
"There are others, the fundamentalists, for whom it would be a much harder sell internally."
That means a genuine reset is very delicately poised. The timing, the political pressures in Belfast and Westminster could all very well militate against a last gasp breakthrough.
One chink of light is that the European Commission and UK officials are close to agreement on a new system which will give EU officials real-time (or as close to it as possible) data on what goods are entering Northern Ireland from GB, so that they can use risk analysis tools to keep checks to a minimum.
Maros Sefcovic has recently highlighted the importance of data in determining the scope of the EU's flexibility.
It will come down to the new prime minister to decide.
Liz Truss faces the huge domestic problems of energy prices and cost of living, meaning she could see the merit in getting the Protocol issue out of the way through a pragmatic deal with Brussels.
Equally she might escalate a clash with Europe to placate the base and keep her party united.
As a cabinet minister who was absent from the great precipices of the Brexit era - the No Deal cliff edge in 2019, the Internal Market Bill standoff in 2020 - and who was absent from the withdrawal and trade negotiations, Truss is both untested and an unknown quantity.
That test will begin when the mourning for Queen Elizabeth starts to dissipate like mist off the Thames.