Monday, 5.36pm: Time's not right for poll on united Ireland. Tuesday, 11.56am: Let's have referendum as soon as possible
It must rank as one of the fastest U-turns in Irish politics. One moment Sinn Fein's new leader Mary Lou McDonald, insists that the time is not right for a border poll. Within hours she does a complete switcheroo and declares that one should be held "as soon as possible".
Unlike Margaret Thatcher in that famous Tory conference speech, it seems this particular lady is for turning.
One can only speculate as to the hullabaloo that must have erupted in republican inner circles in order to prompt such a speedy and humiliating climbdown.
Suffice to say that her ears must be burning from the backlash.
As for what hand a certain bearded former leader might have played in her dramatic change of mind, only Mary Lou can reveal, and, being a loyal party lady, she surely won't tell.
Mary Lou duly got back on-message yesterday by insisting that the risks of a disorderly Brexit showed the "utter failure of partition" and heightened, rather than diminished, the need for people north and south to have a say on their constitutional future.
Crisis averted. But republicans must be scratching their heads in bafflement as to why she said what she did in the first place.
It could be that Mary Lou is a diligent student of Napoleon.
The French Emperor believed you should never interrupt your enemy when he's making a mistake.
With the UK headed for the increasing likelihood of a "no deal" exit from the EU, McDonald may feel that the long-term prospect of Irish unity will be enhanced by letting that process play itself out and seeing how the land lies afterwards, rather than forcing the issue while everything's still up in the air.
And, to be fair, she might be right about that.
As the respected political analyst Danny Dyer recently pointed out, Brexit is a "mad riddle" and no one really knows what's going to happen next. It could well be that adopting a "wait-and-see" attitude is the wisest course of action.
It's still jaw-dropping to hear an Irish republican leader declare a "strong preference" for putting off a vote on Irish unity.
A united Ireland is not just one policy among others; it's integral to what it means to be a republican at all. "England's difficulty is Ireland's opportunity" is the first rule of Sinn Fein's ancient Fight Club.
For Mary Lou to put all that to one side, for whatever cunning tactical reasons, is akin to Donald Trump suddenly announcing that he doesn't think America is that great anyway.
They may have disagreed about the right way to attain unity, but no previous Irish republican leader would ever have made the rookie error of dismissing the removal of the border as a "simplistic" answer to complex questions - even if that's exactly what it is.
It's all the more surprising that Mary Lou did fall into this hole when there's little chance of the Secretary of State agreeing to a border poll in any case, so demanding one on a regular basis is a fairly risk-free strategy for Sinn Fein.
Republicans have always enjoyed the political benefits of pushing for an island-wide referendum on unity, even if privately they think it's not the right time to have one.
Why on Earth would Mary Lou give up the advantages of both having her cake and eating it?
She may, in her ham-fisted way, simply have been trying to make a gesture to match former First Minister Peter Robinson's words at the MacGill Summer School in Co Donegal. His advice during a Q&A after a speech there for unionists to start making preparations for a united Ireland set the cat among the unionist pigeons.
If she really does think there's a game-changing conversation going on in pro-Union circles as to the benefits of Irish unity, she might have concluded that slow and steady wins the race, and that it's best to let such a debate take its natural course without scaring away potential allies with the imminent threat of a change in the constitutional status.
If so, she's likely to be disappointed, but it wouldn't be an unreasonable position for the Sinn Fein leader to adopt.
Whatever the real reason, Mary Lou's unilateral shift on the issue of a border poll can only confirm suspicions among the party's northern supporters that her eyes are fixed on the main prize of government in the Republic, probably alongside the ruling Fine Gael party.
The Republic's Minister for Foreign Affairs Simon Coveney flirts with old school nationalist oratory, but his horror at the idea of a border poll is entirely genuine. Taoiseach Leo Varadkar has also said the time isn't right.
Mary Lou's original remarks were, surely, intended to demonstrate to future coalition partners that she is ready for responsible, grown-up government rather than protest politics.
Republican hardliners always feared this might happen if they had a leader without the same roots in the "struggle", especially one who didn't even start out in the ranks of Sinn Fein, but shifted over from Fianna Fail.
They bristled when she uttered the dreaded word "Londonderry". Now this.
Whisper it gently, but Mary Lou may just be discovering that she's out of her depth and has no clue how to balance the competing demands of being leader of a party with two distinct, sometimes conflicting, interests and identities.
North of the border she has to play up the tough, anti-partitionist rhetoric in an effort to appeal to grassroots activists weaned on conflict.
South of the border she needs to be seen as a safe pair of hands to get into government after the next election. Mary Lou simply has no idea how to bring those strands together in a coherent political philosophy.
Probably because they can't easily be reconciled.
She's forced instead to oscillate wildly between the two impulses.
What must now be obvious to more traditional republicans is which of these rival demands commands her greatest personal sympathy.
The statements which Mary Lou made opposing a border poll in that Press Association interview were not some off-the-cuff asides, after all. They were part of a long and thoughtful discussion about the future.
She couldn't have said what she did on the video, in the careful and detailed way that she did, unless she absolutely meant every word. Even if, as a dutiful republican, she recognises the opportunities in a little post-Brexit chaos, her deeper desire for economic and social stability won out.
She was unceremoniously yanked back into line, but clearly the moderate Fianna Fail-er in her has not been entirely erased by the mask of the populist Sinn Feiner.
If hardliners suspect the party's aim under Mary Lou McDonald's leadership will be to tinker with the finer points of partition rather than prioritise getting rid of it altogether, who can now tell them that they're wrong?