What changed? That was the question reporters scrambled to answer in Hanoi yesterday as Donald Trump's tête-à-tête with Kim Jong-un morphed from apparent progress to no-deal.
Yesterday morning all signs pointed to an agreement of sorts being reached. Kim was answering questions from US reporters and talking up his willingness to denuclearise.
Trump sounded upbeat about stationing diplomats in Pyongyang permanently.
The pair were seen trading smiles during a poolside stroll at the luxury Metropole hotel.
The White House was so confident in the direction of the talks on Wednesday night that they even scheduled a signing ceremony.
And then, suddenly, the deal was off.
One reason for the collapse in talks was the gap over denuclearisation. Kim wanted all economic sanctions lifted without giving up his nuclear weapons,
Trump explained later. He himself was not willing to sign such an agreement.
But sceptics looking for clues raised another, less probable but more provocative question.
Did a desire to bounce Michael Cohen's testimony out of the headlines play a role?
Back in Washington, the explosive claims by Trump's former lawyer and "fixer" for a decade had overtaken the president's talks as the day's biggest news story.
Before a congressional committee, Cohen had claimed Trump was a "racist", said he had forewarning about a WikiLeaks dump of Democrat emails, and revealed a $35,000 ($50,000) cheque from the president allegedly paying back hush money.
The Washington Post, New York Times and LA Times all led with Cohen's incendiary claims on their front pages yesterday.
Trump was clearly riled by the coverage.
On Wednesday evening, back in his hotel before meeting Kim, the president wrote on Twitter that Cohen was lying to reduce his jail time.
At a press conference, he admitted to watching some of the testimony and expressed fury that the hearing was scheduled during his summit.
"Having a fake hearing like that and having it in the middle of this very important summit is really a terrible thing," Trump said.
The House committee in question is controlled by the Democrats.
Trump has a track record of being irritated when domestic woes undercut his deal-making abroad. He once reportedly complained that a world leader questioned how long he would be in office because of the Russia probe.
But is it really possible Trump would torpedo his own North Korea talks to knock
Cohen's claims off the news? It seems a stretch.
The distance between both sides on denuclearisation is real.
Late last year, Pyongyang's frustration at the US refusal to lift sanctions until all nukes were given up contributed to a breakdown in talks.
Curiously, other "wins" being discussed at the negotiations which seemed obtainable - formally ending the Korean War, for example - were left by the wayside.
Exactly why Trump opted not to reach for some of them and create a face-saving compromise, remains unclear.
But whatever the intention, come yesterday evening it was the summit's collapse, not Cohen's allegations, that were leading the US headlines.