There have been meetings upon meetings. There have been coffees, drinks, dinners. Two MPs in the corridor is a meeting. There are only two things to discuss: who is to be Prime Minister and what it means for them.
It mattered at the start that John Key endorsed Bill English. But now Key is now just another vote in caucus.
It's a tough process choosing a leader. It's especially so when it also means choosing the Prime Minister. There are a lot of jobs up for grabs and an election less than a year away.
It's also not something MPs are experienced in. National has enjoyed 10 years of success and stability. Over half the caucus know no other leader. They have no experience in changing leader or how to behave. National has senior Ministers who have never been through a leadership change.
It's tough and each MP is alone with their vote. It's very different to voting with the party on government policy.
Leadership votes are hard on friendships and hard on collegiality. And although only the MPs have a vote, everyone they know - and some they don't - has an opinion and wants them to listen.
There are few rules. Just a vote. And a result.
If you think it's easy consider just two simple questions: at what point do you commit your vote? And what do you do when you change your mind? Spare a thought for the MPs: they're having a long, tough, tortuous and highly emotional week.
The "why not me?" question is popular in politics by the nature of the job. In other jobs you have to produce things. You know yourself how good you are. There is an obvious measure.
There's no such measure in politics. There's an army of civil servants working away to make Ministers look good. Very mediocre politicians can do well just doing what they are told. That's not lost by the back bench. If so-and-so can do it, so can I.
In politics it's impossible to determine if someone is any good until they are in the job. Some stars prove tragic. Some tragics prove a surprise.
Something else has also been happening. Would-be Prime Ministers and deputies have been telling backbench MPs how truly outstanding they are. That prompts the "why-not-me" question every time.