"Julia was my loyal deputy. And I didn't believe she would do that. Until that point." – Kevin Rudd

In December 2009, Prime Minister Kevin Rudd left for the Climate Change conference in Copenhagen, leaving behind a turbulent period in domestic politics. Action on climate change was one of the defining issues in Rudd's rise to power and with a new opposition leader hostile to his emissions trading scheme, Rudd's political credibility became linked to the outcome.

But Copenhagen failed to deliver a decisive result and a deflated Rudd returned to Australia. Gillard now claims the disappointment in Copenhagen had a devastating effect on Kevin Rudd.

Spooked by Tony Abbott's campaign against the Government's "great big new tax" on carbon and negative internal polling on the ETS, the Government shelved its signature climate policy. A Newspoll on 4th May showed the Government lost a million voters in a fortnight.

With the 2010 Election looming, Rudd's Government moved from crisis to crisis – with the mining tax, and asylum seekers dominating the headlines, as well as concerns over rising debt.

Party insiders began to contemplate a change in leadership. Now for the first time, both sides lay bare their accounts of the preparation and execution of the challenge. According to one of the players, "In terms of its professional execution… you'd have to say it was the best."

In the final act of the episode, Rudd and Gillard give the inside story of their contentious closed-door meeting on the night of 23rd June 2010…