The outbreak in Auckland has reached a sobering point, meaning vaccination is now Auckland's only way out of lockdown.
How long that will take depends on the vaccination efforts in communities that are most at risk of the virus leaving behind a trail of destruction - those both vulnerable and unjabbed.
At the start of last week, there was still a glimmer of hope - epidemiologist Tony Blakely gave it a 5 per cent chance - that the outbreak could be extinguished by a combination of level 3, the vaccine rollout, and public health teams hunting the last cases.
But it has now grown to a point where that is no longer possible, with Covid-19 Minister Chris Hipkins warning Aucklanders to brace for exponential growth in case numbers.
"There's no question we're going into a period where we are likely to see quite significant growth in the number of cases," he said.
That means level 2 movement in Auckland cannot be safely permitted until there is high vaccination coverage.
Prime Minister Jacinda Ardern has talked about leaving no group behind. This means 90 per cent coverage of the eligible population means little if there are still pockets of thousands of unvaccinated people who would be in the virus' crosshairs at level 2.
Most of the suburbs where the virus is entrenched have first-dose/second-dose coverage lower than the Auckland average (87 per cent/64 per cent).
They are: Mangere Central (74.1 per cent/51.1 per cent), Clover Park North (75.9/54.5), Favona East (77/55.7), Papakura Central (81.7/59.7), Red Beach East (88/64), Manurewa Central (84.8/62.2), Henderson Central (82.3/64.2), and Mount Wellington Central (89.4/70.2).
And we know that the vaccination rates among young Māori and Pasifika - the groups that make up the majority of known active cases - will be much lower than those figures.
We also know that the virus has now spread beyond those suburbs, with locations of interest reaching almost all corners of the city - from Devonport to Hobsonville to Pakuranga.
"It's right across Auckland," says Māori GP Rawiri Jansen, who has been helping those on the frontline with getting people tested and vaccinated.
"It's going to travel among younger people who are more social, more connected [and less vaccinated], and then it will land in houses of seven or 10 people.
"Super Saturday could be followed by Hundy Sunday."
And case numbers will keep going up, as the impact of allowing outdoor picnics is still yet to come through in daily case numbers.
Contact-tracing capacity might reach saturation point in coming weeks, and MIQ facilities could fill up, triggering DHB plans for home quarantine.
It's arguable that the tipping point was three weeks ago when Ardern moved Auckland out of level 4 restrictions at a time when there was still community transmission, or last week when she eased level 3 rules when cases were trending up.
She was trying to walk a fine line by allowing more freedoms in a way that didn't increase the public health risk, when the case numbers were still low enough to return to zero.
The risk - which Hipkins argues was there regardless of the move to level 3 - was that the outbreak would grow, with young Māori and Pasifika bearing the brunt.
Says Jansen: "We have thrown everything at this in terms of containing every cluster, every household, and we've done a very good job, to be honest. But Delta is so transmissible and so difficult."
Whether the outbreak will grow so quickly that it will overwhelm Auckland's hospitals remains the key issue.
Covid-19 modeller Professor Michael Plank estimates cases hitting 160 a day by early November.
That's 1120 cases a week, which is 112 cases in hospital a week, based on the hospitalisation rate for the current outbreak.
Epidemiologist Professor Michael Baker says a reasonable estimate from those numbers is that 17 people a week would need ICU treatment.
On Monday, there were 133 ICU/HDU beds across Auckland's three DHBs; 90 were occupied. Contingency capacity can be used but the opportunity cost is someone's elective surgery.
Pressure on the health system - including staff being stood down after potentially coming into contact with the virus - could be alleviated by a circuit-breaker level 4.
But Hipkins said that wasn't being considered because of the likelihood of rule-breakers.
The thinking is that compliant Aucklanders at level 3 is better than some Aucklanders flouting level 4 rules.
All this makes this period - the weeks or even months until high enough vaccination levels - an anxious one.
Aucklanders will be shielded from the worst impacts of the virus if they continue to follow the rules, and if the current momentum in the vaccination campaign continues.
The consequences of either of those falling over is terrifying to contemplate.