Why is Theresa May rushing to Brussels on Wednesday when she has a fair few political headaches to contend with back home, and when she's due back here in just a few days for the seal-the-deal Brexit summit of EU leaders?
The answer: the prime minister wants to show she is fighting until the very last moment to get the best Brexit deal possible out of the EU.
Her Wednesday afternoon visit to see Jean-Claude Juncker, the head of the European Commission, provides her with a floodlit platform to do so.
Now, the plan had been for the two leaders to discuss a draft text of the political declaration on post-Brexit EU-UK relations.
Mrs May wanted to push for even closer trade ties than the EU has been willing to concede so far without the UK staying in the single market.
Essentially she is very, very keen for her Chequers proposal for Brexit (viewed in EU circles as cherry-picking non plus ultra) to be reflected in the document.
However, the Brexit process has now got a lot more complicated - meaning that the draft text on EU-UK future relations hasn't been finished in time for the prime minister to pick over.
You see, it's no longer just a matter of Mrs May wanting more from the EU.
A number of EU countries are suddenly pushing for a lot more from the British prime minister. For France, it's about fishing rights; for Spain, it's about the status of Gibraltar.
Others, meanwhile, such as the Netherlands and Denmark, think she should be getting a whole lot less when it comes to the UK-wide customs union, envisaged as part of the backstop for the Irish border. They want the UK to be tied tighter to EU environment regulations, for example, to avoid UK business having a competitive advantage over Europeans.
As for the PM's Chequers plan for trade and security (much maligned back in the UK, too, of course), Germany has said loud and clear it won't allow the political declaration on future EU-UK relations to be a means of what Berlin describes as "Chequers by the back door".
It is highly unlikely that all this can be sorted out in just one meeting between Mrs May and the European Commission chief.
So the big question is: will the draft text on EU-UK future relations be ready by the end of the week to give EU leaders at least one day to digest it? Or are the stars aligning for a dramatic showdown between those leaders and the UK prime minister at their Sunday summit?
One EU diplomat predicted possible similarities with a nail-biting, marathon summit at the height of the Greek debt crisis.
During the all-night meeting, Greece's Prime Minister Alexis Tsipras was invited to make his case to eurozone leaders on a number of occasions, before being sent out of the room to allow those leaders to decide the economic fate of his country amongst themselves.
EU rules do not allow Mrs May to negotiate Brexit with EU leaders directly. If a number of issues remain open on Sunday, their Brexit summit could turn out to be a lot, lot longer than the two-hour signing session and photo op originally envisaged.
The last question I'm going to ask in this post now is: could this all be more about optics than nitty-gritty politics?
Grumbling aside, no-one in European circles seriously thinks any EU country will refuse to sign up to the Brexit deal by end of play this weekend.
They're all keen to avoid a no-deal scenario and they want to help Mrs May get the Brexit texts through a vote in the House of Commons.
Engaging in last-minute political fisticuffs with the EU is arguably advantageous for her.
A high-drama, climactic Brexit summit ending in a late night/early morning bleary-eyed but triumphant resolution with EU leaders would allow Mrs May to claim that the final text of the deal was hard fought and hard won… in the fervent hope that will soften the stance of some of her many critics at home.