This week's EU summit in Salzburg should settle three important Brexit questions - of profound important to this country's future and that of the PM too.
Most importantly, the leaders of the EU 27 are being asked by their Brexit negotiator Michel Barnier and the EU president Donald Tusk how specific and prescriptive they want the Political Declaration on Britain's prospective relationship with the EU to be.
In a way it is astonishing, with just six months to go before we're out, that Barnier and Tusk do not know something so fundamental about their wishes.
And truthfully it is mostly about finding out from the German chancellor Angela Merkel whether she has backed away from President Macron of France and his desire for the framework of the future partnership in commerce and trade, security and foreign policy to be established in some detail and certainty now.
To be clear, the judgement the leaders are are making is more about the state of British politics than about the fundamentals of how they see their future links to the UK.
In part they have to take a view on what kind of declaration is most likely to secure a yes vote in the British parliament - because they would see parliamentary rejection that led to a no-deal Brexit as a bad accident rather than a possible policy outcome. Unlike May, they have never signed up to the mantra that no-deal is better than a bad deal.
For what it's worth, I see no sign that EU leaders will ever sign up to the PM's proposed common rule book for goods trade alone, or her two-tier tariff system via her Facilitated Customs Arrangement.
So the question for them is one of presentation rather than substance: do they decide to kibosh Chequers now or in six months, to spare the PM's blushes and because they think the House of Commons more likely to vote for a “blind” or “jamboree bag” Brexit than a Chequers Brexit?
My guess is they will conclude that ripping the heart out of the PM's Chequers plan is simply too bad manners at this juncture - since they'll fear the PM would never survive.
But I might be wrong.
And one reason I might be wrong is that they are increasingly fed up with what they see as May's refusal to engage constructively with them on their “backstop” proposal to keep open the border between the Republic of Ireland and Northern Ireland.
To remind you, their proposal for Northern Ireland - to have separate customs and product standard rules from the rest of the UK unless and until some other long term solution is agreed - is anathema to May.
And EU leaders know that what is most likely to cause a chaotic no-deal Brexit is failure to find a compromise here.
There is little sign that their proposed technical solution, that UK customs officials, not EU ones, would inspect goods flowing from GB to Northern Ireland is remotely acceptable to May.
That said, they seem in little mood to move further.
So the second really important decision they have to take is whether to show less solidarity with Dublin than hitherto and embrace in some way May's plea for any backstop to apply to the whole UK and not just Northern Ireland (to avoid what she sees as the risk of Brexit fundamentally weakening the bonds between Northern Ireland and the rest of the UK).
Finally there is the question of when we'll know whether it's deal or no deal.
It is very likely EU leaders will announce a new timetable for agreeing both the legal text of the Withdrawal Agreement and the Political Declaration on the future relationship.
That should set an imperative of making important progress at the formal summit on 18-19 October, with a view to finalising agreement at an emergency summit in mid November.
At which point, if all went to plan, there would be a deal.
But - and please don't jump out of the nearest window at what follows - this doesn't mean Brexit would then be settled, and orderly, because parliament has been promised by May “a meaningful vote” on all this.
Which means MPs have every right - and some of them have every intention - to reject whatever May finally brings home from Salzburg and then Brussels.