In two months Jacinda Ardern took Labour from flatline territory to challenger status, writes Claire Trevett.
Within just a few weeks of first saying "let's do this", Jacinda Ardern had already done it.
Labour's polling had returned to the 30s and soon after that the party was breathing down National's neck.
Make no mistake, Labour's change in fortunes was almost singlehandedly down to Ardern.
She also turned the election into a nail-biter and was probably gobsmacked at the swift change.
Her first goal was to lift Labour out of flatline territory - even if she had to be ruthless to do so. That meant getting the easy voters first.
Her targets were those who were also key to the Green Party: urban, environmentally conscious, housewives and the young, in particular students.
Ardern "tweaked" Labour's offering to entice both - the clean rivers policy with water charges that would apply primarily to the rural sectors and the target to be carbon neutral by 2050 for the housewives, and the promise of three years' free post-school education or training for the youth, combined with more generous student allowance and loan payments.
Everybody wanted to say they were "voting for Jacinda" and the Greens vote collapsed in half.
The Memorandum of Understanding both parties signed with much back slapping last year was the campaign equivalent of the character of Bernie from Weekend at Bernie's on the campaign trail. Ardern pretended the corpse was still alive when it was anything but. There were no electorate deals. Ardern and Green Party co-leader James Shaw barely saw each other on the campaign trail, let alone did any joint events.
With the help of friends in the creative sector Ardern whipped out new advertising, smart social media ads and regular Facebook Live videos. The music was a faster tempo. The red-heavy advertising Labour had been using was reversed so the white was dominant - a much fresher and brighter look.
English had a more intensive diary than Ardern but if English campaigned on foot leather, details and his record, Ardern campaigned on hope and change.
She was one of the very few politicians who could carry it off without sounding corny to a more sceptical New Zealand public. Grown men were entranced.
She used the language, oratory and the techniques of American campaigns - hope, vision, values, "better", change, change, generational change and promise.
She held big rallies of Labour supporters, waving hoardings and cheering at every turn. The rallies were opened by celebrities - comedians and musicians: Michele A'Court, Hollie Smith, Anika Moa, and an ensemble of musicians from Fat Freddy's Drop, the Black Seeds and Phoenix Foundation.
When things turned sour, Labour again drew on America to dismiss National's attacks on tax as "fake news" and "alternative facts".
It was not all smooth sailing.
Ardern learned there were limits to how far her personal appeal would carry her. Her first - and possibly only - real mistake was in believing the response meant voters would let her get away with going into government without a clear tax policy.
In that, her predecessor Andrew Little's initial judgement - that no changes could be made without taking them back to the electorate - had proved the right one.
It also blunted Labour's ability to claim National had had nine long years to resolve problems such as homelessness and poverty. Labour too had had nine long years to come up with a full suite of policies.
Her biggest test was the follow-on - her handling of National's concerted attacks on that tax policy. It was at that point that Labour's progress in the polls stalled.
Ardern learned the ability to inspire did not necessarily trump certainty and security. Her backdown on that matter showed she had learned - but she was never quite able to put to bed the question marks over her tax intentions.
Ardern was backed by a crew of supporters - veterans Annette King and Trevor Mallard among them. Mallard took on practical duties, such as holding umbrellas. King was hand-picked as a sage head and Ardern's mentor.
To capitalise on the momentum and ensure the "stardust" survived until polling day, Ardern took fewer risks with her campaign than English.
She did not have the baggage of English so the risk of hecklers was lower but, by and large, she avoided situations where she might come across critics.
She was campaigning on relentless positivity and she wanted it in return. She went where she would be adored and she was.
There will be a hangover from the campaign. Whether Ardern admits it or not, her bid to secure youth voters has left some older voters feeling excluded. The sense in rural communities that the farmers and horticulturalists were being targeted was real and will have alienated many.
Some pondered whether seven weeks as a leader was enough or whether Ardern's "turn" might be better held off until 2020.
But nobody doubted that she would be the Prime Minister at some stage.