"Malcolm was passionate on the phone when he rang," says one of those seduced by his call. "He was not nasty about Brendan."

A jet-lagged Turnbull, who had arrived in Sydney just before 6 o'clock that morning on a flight from Dubai after a week's holiday in Venice with his wife, Lucy, was caught out by Nelson telling a snap meeting of Liberal MPs there would be a spill of his nine-month-old ailing leadership the following morning.

"It's time. It's on," a defiant, angry Nelson told the party room. But the doctor was on borrowed time.

Until he moves to the leader's suite tomorrow, Turnbull's office is directly across the corridor from the party room, literally a few steps. Until this moment the loose collection of MPs supporting him claim to have never held a formal meeting or even gathered for a drink to discuss tactics.

But now, suddenly out of the shadows like J. K. Rowling's Death Eaters, they began to materialise in Turnbull's office to launch their campaign. Among those who visited suite RG 115 that evening were Michael Ronaldson, Steve Ciobo, Greg Hunt, Scott Morrison, Alex Hawke, Christopher Pyne, Chris Pearce, Michael Keenan, Andrew Robb, Peter Dutton and Tony Abbott.

Turnbull declared that he would contest the ballot, sat at his desk with his phone and laptop and opened a spreadsheet listing the names of all Liberal MPs. He divided them into three columns: those for him, those for Nelson and those undecided. Significantly, the right wing of the party, having backed Nelson last year, split. Morrison and Hawke secured key NSW votes for Turnbull, including Concetta Fierravanti-Wells and Pat Farmer.

Turnbull spoke to Alexander Downer, who had become a counsellor of sorts. He'd also had advice at irregular intervals from the former NSW Liberal minister Michael Yabsley, who set up the Wentworth Forum to raise funds, and the Victorian Liberal identity Michael Kroger.

Kroger had been against Nelson's leadership from the start and had clashed with his best friend, Peter Costello, over the issue. Eventually they agreed not to mention it to each other. Most of the "Costello camp" defected; Nelson got just three of its votes - Costello, Tony Smith and Mitch Fifield. In a sign of the changing forces inside the Liberals, about 12 who had been staunch supporters of the former treasurer voted for Turnbull, including Ronaldson, Pyne, Pearce, Ciobo, Keenan, George Brandis, Brett Mason, Helen Kroger (Michael Kroger's former wife) and Scott Ryan.

Nelson would have survived if he had called the vote immediately. But he was too decent to completely ambush Turnbull, say his supporters, who believe he made fatal errors such as telling MPs he would not lobby them for support. "I'll be in my office. You all know me and my record as leader. I won't be lobbying." They were welcome to visit or call him. Many did, but a crucial few others who might have been persuaded were lost.

In his party room speech Nelson laid out his frustration and savaged those he said were working against him and drowning out his successful attacks on Labor over pensions and petrol. "People in this room have been briefing against me. You know who you are. I know who you are."

When Ronaldson observed that it was a "very short period" before the morning ballot and wondered if absent colleagues would miss the vote, Nelson gave his anger a specific target. He snapped at the Victorian senator, furiously waving around press clippings he said proved malicious leaking and quoted from one, from The Age of the previous Friday, which he slammed down on the table. He didn't say it, but everyone in the room knew he was accusing Ronaldson of leaking against him, although there was no proof.

A second tactical error was Nelson's threat that if re-elected he would make "significant changes to the front bench and my office". The tough talk injected more uncertainty even for supporters.

Abbott had infuriated and weakened his leader by his public pleading for Costello to save the party. Nelson had decided to take the risky step of dumping Abbott from the front bench. For every Liberal who can't stand Tony Abbott, another adores him. It appears Nelson intended to also chop Ronaldson, Ciobo and others.

Nelson's supporters flooded the media. Fifield, who voted for Turnbull last November, told Sky News he was backing Nelson: "I don't think Brendan has been given a fair go." The key frontbencher Tony Smith delivered the same message. In the days that followed, there was much speculation by MPs about the role of the two former Costello staffers switching their vote and doing so publicly.

Ciobo was not at the party meeting. He was due to attend a portfolio-related dinner in Melbourne but his 5pm flight had been cancelled and he was still delayed at Canberra airport when he heard about the spill. He rushed to Turnbull's office to work the phones.

Robb had tried to walk the fine line between supporting Nelson while also believing Turnbull was the best bet. He thought Nelson might scrape in and leave the party paralysed. He spent the night talking to MPs in the dining room, the corridors and their offices to persuade them to change leader.

At one point he considered challenging Julie Bishop for the deputy leader's job but backed off out of concern his move would upset women and derail Turnbull.

Bishop lost a lot of confidence in Nelson's judgment in July when he mishandled the emissions trading scheme policy and she felt personally burnt by his erratic behaviour. She spoke to both leadership contenders on Monday night and many Liberals believe she voted for Turnbull. She won't say, but it is telling that Nelson did not bring her into his confidence. She received the "urgent message" sent by fax and pager by the Chief Opposition Whip, Alex Somlyay, at the same time as everyone else calling them to a "special Liberal Party room meeting at 6.30pm" because "the Leader, Brendan Nelson, has important matters to raise".

Nelson had been thinking about a pre-emptive strike for three or four weeks. By the time Liberal MPs past and present gathered in the Parliament's Great Hall on September 3 to honour John Howard, Nelson had decided it was the only option to address the constant speculation about his longevity in the job.

He knew Costello's memoirs were to be published in the Herald the following week and that the former treasurer would be puncturing the fantasy of many Liberals by declaring that he would not be the white knight who would take over the ailing Liberals.

Turnbull had gone out of his way not to say or do anything about the leadership, but his supporters and others had marked the release of The Costello Memoirs as the beginning of the countdown on Nelson's tenure.

There were various scenarios in which mid-October, late November and even early next year were seen as possible time frames for a challenge. Others were insisting no challenge would be needed because, as with Downer's ill-fated reign in 1994 and 1995, it would just become apparent that change must occur.

Nelson would not wait for the slaughter. He was determined to fight for the job; if he had to go, it would be on his terms. Over the next fortnight he confided in just a handful of MPs and staff. He reached boiling point when he read in a Sunday newspaper that Turnbull had granted him a "stay of execution" for a month.

Not surprisingly, Nelson's supporters are cagey about what they knew and when. Nelson had told his chief of staff, Peter Hendy, and a few trusted advisers but deliberately kept another top adviser, Tom Switzer, out of the loop. Nelson told Peter Costello, Nick Minchin and Tony Smith "a little ahead" of the announcement.

Some had plenty of warning. Nelson asked the NSW South Coast MP Joanna Gash to secretly delay her departure to New York as the Liberal representative for three months at the United Nations. "I need your vote in the party room," he told her.

Yet Nelson gave no warning to another fiercely loyal mate, Bob Baldwin, who took it upon himself to mount a defence. "Brendan did not ask me to make any calls whatsoever, but I had been called by others asking what I was going to do," he says. "I made it very clear I was supporting him. I said my view was Brendan had done nothing wrong. People were constantly undermining him and his ability to get his message out. It's one thing when the opposition does it to you. It's another when it's your own team."

Jamie Briggs was waiting to be declared the winner of Downer's old Adelaide Hills seat of Mayo when Somlyay called at 7.30pm on Monday to tell him he was eligible to vote.

Briggs, who had worked as Howard's industrial relations adviser, called the former PM to discuss the ballot. Howard told him to vote for the person he thought was best for the party. Briggs also spoke to Downer and Hunt, who urged him to vote for Turnbull.

On Tuesday, while he waited for his 6.35am flight from Adelaide to Canberra, Briggs spoke to Turnbull and Robb. He told Turnbull he was likely to vote for him but hoped there wouldn't be any retribution against Nelson or his key supporters such as Nick Minchin. Turnbull gave that assurance.

His plane landed at 8.35am but sat on the tarmac for 15 minutes. He worried he would not make the 9am party room meeting.

Somlyay was in constant contact by mobile phone. Nelson and Turnbull agreed to wait. To some it seemed comical as the Whip gave progress reports. After 10 minutes Western Australia's Don Randall suggested they wait no more. "He's in the driveway," Somlyay yelled.

It was an extraordinary debut meeting for Briggs. He got a standing ovation and a short welcome speech from Nelson, who then announced the spill and nominated himself. Turnbull stood and nominated himself.

Five minutes after entering the room, Briggs was writing Turnbull's name on the blue ballot paper. Two old wooden ballot boxes, relics from Old Parliament House, were used to collect the votes.

Nelson sat next to Pat Farmer, who leaned across and quietly whispered: "Would now be a good time to ask for an extra staff member?" Nelson replied, "Sure, mate".

The count took place in an ante room. Somlyay returned to announce that Turnbull had been elected. Christopher Pyne asked what the count had been. Somlyay had been holding this back because he didn't want the detail sent from the room by text message. He revealed the 45-41 result as he walked out to announce it to the press. Nelson and Turnbull shook hands; there was applause.

The leadership secured just four years after entering Parliament, the next questions for Turnbull concern the make-up of his front bench and the style and policy changes he will bring to the Liberal Party, including the conduct of its mostly moribund state divisions. Suggestions the front bench would be named yesterday evaporated as the task of balancing rewards for supporters and inclusiveness for opponents became apparent in all its unwieldiness.

As to style and policy changes, Liberal sources have little to illuminate because Turnbull has had little to say. Will the Turnbull reign eliminate the last vestiges of Howardism? Watch this space.

"The Howard agenda was set in the early 1990s and has washed through," says one MP. "It's time to move on. We've got to move forward and got to find ways to be attractive to the electorate."

Says another: "There is a sense of excitement about Malcolm. He's an ideas man. He brings economic credibility and will sharpen our attack on the Government."

Labor already appears a little rattled by the arrival of Turnbull, who may also challenge Kevin Rudd in the workaholic stakes. After the frantic pace of Monday's pitch and the speed of Tuesday's victory laps, Turnbull concluded a marathon Wednesday with an email to a colleague. It was 3.12 on Thursday morning. Two hours and 13 minutes later, his night's sleep behind him, Turnbull sent the first email of a "new" day to one of his staff.