As late as Wednesday morning the four conspirators behind one of the most unlikely press conferences in Australian political history were still not completely convinced it would go ahead.
It wasn't until Al Gore stepped off the plane in Canberra that Don Henry, Ben Oquist, Andrew Crook and John Clements breathed a sigh of relief.
Clive Palmer's headline-grabbing double act with Mr Gore may have appeared impromptu but the former US vice-president's road to Canberra began months earlier.
Mr Henry - until this year the long-serving chief executive of the Australian Conservation Foundation - had already organised an Australian visit as part of Mr Gore's climate change education venture. Mr Gore sought Mr Henry's advice about meeting other people in his brief time here. Mr Henry suggested Mr Palmer, given his party's crucial role in Senate.
Mr Henry was unsure if a meeting would happen. Mr Palmer was openly sceptical about humanity's role in climate change.
But Mr Henry nonetheless reached out to Mr Clements for an introduction to the Fairfax MP.
To some surprise Mr Palmer agreed to consider it, and in the following weeks Mr Henry negotiated with the Palmer United Party leader on Mr Gore's behalf. And through the discussions Mr Palmer began indicating a shift in his position on climate change.
At the same time Mr Clements - a long-time staffer to former independent MP Tony Windsor - was lobbying Mr Palmer about the importance of the climate change measures agreed by the previous parliament. As an insider explained, for Mr Clements "there were legacy issues involved in protecting elements of the package … he was interested in protecting the [Clean Energy Finance Corporation] and the [Renewable Energy Target]''.
Mr Oquist, a former chief of staff to Greens leaders Bob Brown and Christine Milne - now with The Australia Institute - was also working on the MP.
Mr Palmer and Mr Oquist first got to know each during negotiations over preferences for the 2013 election. Even after leaving the Greens, Mr Oquist kept communication open with Mr Palmer, a politician always looking to expand his base.
Mr Oquist lobbied him to consider the merits of the Climate Change Authority, the money-making Clean Energy Finance Corporation and the possibility of a zero-dollar emissions trading scheme. He also pushed the benefits of the Renewable Energy Target, under review by the Abbott government and supported by few Coalition MPs.
As one insider familiar with the negotiations told Fairfax Media: ''There were two parallel things going on. Ben was talking to Clive, and that just merged with Don bringing Gore out.
''We only knew it would happen when Gore got off the plane at Canberra airport. At every point it could have fallen over, though the closer we got, the greater the likelihood it would come off.''
There was also an ally in Mr Palmer's staffer Mr Crook, who immediately saw the potential boost for his boss of a joint Palmer-Gore appearance in Canberra.
Mr Palmer agreed to back the financing corporation, a position some PUP senators had already warmed to. But for Mr Gore to get on stage, Mr Palmer had to swing behind the renewable energy target. ''Clive had to move on the RET and that only happened over the weekend,'' another insider said.
''It was Clive and his team, he talked to his party room, they met on the weekend, and it was their final decision.''
By Wednesday Mr Gore, Mr Henry, Mr Palmer and staff sat down for a meeting before the announcement later that evening.
Mr Gore is understood to have impressed on Mr Palmer that the rest of the world was already acting on climate change and Australia would become a laggard if it did not move to cut emissions.
And he told Mr Palmer Australia's current carbon pricing regime should be kept.
But while the PUP moved on the target, any weakening of party's position of repealing the carbon tax was a non-starter in the party room. Mr Palmer's senators felt they had been elected on a pledge to repeal the legislation.
After the announcement there was confusion whether the PUP support for repealing would be contingent on the establishment of a zero-dollar emissions trading scheme, which it is now proposing.
Initially Mr Palmer's staff briefed this was the party's starting point. But Mr Palmer later quashed that position on Lateline.
Before the announcement Mr Henry, Mr Gore, Mr Oquist and others knew they did not have a deal for repeal to be contingent on a trading scheme. Mr Gore had doubts about standing next to Mr Palmer as he backed the abolition of Australia's price on carbon, but he was convinced the advances made still merited his presence.
Mr Henry told ABC radio on Thursday that Mr Gore had not been ''played'' by Mr Palmer. He said Mr Gore did not give his blessing to axe the carbon tax but saw the merit in saving clean energy infrastructure and a commitment to an emissions trading scheme.
The government claimed victory with the repeal of the carbon tax going ahead. The rest of Mr Palmer's demands will be negotiated.
Late on Wednesday night in Parliament House, Mr Gore and Mr Palmer again took centre stage at a dinner for about 20 people.
Mr Clements, Mr Oquist, Mr Henry and Mr Crook were on hand. So were Mr Palmer's children. The discussion turned to climate change often.
Elsewhere in the building, government strategists were redoing their political calculus. The carbon tax would go, but Mr Palmer, for now, was here to stay.