The numbers game will soon be on.
Bill English's resignation as leader of the National Party takes effect on February 27 - the party's 56 MPs have two weeks to choose a successor.
Potential candidates will be weighing up their chances, and over the next few days they'll be announcing their intentions.
Simon Bridges, Judith Collins, Jonathan Coleman and Amy Adams could all be in the running.
Of those four, only Ms Adams didn't stand for the leadership when John Key resigned as prime minister.
Nikki Kaye could decide to go for it, and there are some ambitious backbenchers who might fancy their chances.
There's sure to be a strong debate within National about whether the party needs a woman leader to take on Prime Minister Jacinda Ardern in 2020, or whether experience, competence and voter appeal should be the deciding factors.
Unlike Labour and the Greens, whose members have input when a leader is chosen, National's caucus makes the choice on a majority vote.
Mr English made a dignified exit and has left the caucus a clean slate.
After that, the party won't want any messy back-stabbing over who succeeds him.
It's possible, but unlikely, that behind-the-scenes wheeling and dealing could deliver an agreement to back one MP as the leader and another as the deputy.
The current deputy, Paula Bennett, has given no indication that she wants either position.
Mr English will leave parliament altogether on March 1.
He had been expected to hand over the leadership well before the next election, but not this early.
His announcement took the caucus by surprise on Tuesday.
On Thursday and Friday last week MPs put on a show of unity at their caucus retreat, lining up behind Mr English and Ms Bennett.
It's clear now that while that was happening, Mr English had already made up his mind about his future.