It appears the genomic sequencing is the game-changer we hoped it would be.
This morning Covid-19 Response Minister Chris Hipkins said the initial results show a strong likelihood that the mystery Auckland case, a student in her 20s, is linked to the Defence Force cluster.
Knowing the source is critical and this would make a return to lockdown unlikely.
Here's what we know about that group, also called the November quarantine cluster.
Last week a Defence Force serviceman caught Covid-19 from cases in quarantine while working at the Jet Park quarantine facility. His Covid strain matches cases in the Jet Park.
How he caught it remains unclear, but Defence Force staff interact with cases when they are escorted to the exercise area or for a smoking break.
The 241 Defence Force staff with whom he shares accommodation in Auckland have all tested negative.
On Wednesday last week he had a meeting with a Wellington-based Defence Force civilian worker in Auckland.
She then flew back to Wellington on Thursday and, on Friday, had lunch with three other people at Little Penang on The Terrace in Wellington.
The serviceman felt ill and returned a positive test on Friday. That evening the civilian worker developed symptoms. Genomic sequencing shows she caught the virus from the serviceman.
She was tested the next day and a positive result was returned on Sunday. A person on her flight caused alarm when they felt ill after attending a meeting in the Waikato, but they tested negative.
The civilian worker has 56 close contacts who all tested negative except for one - another Defence Force worker at the Little Penang lunch on Friday.
That worker, a woman in her 40s, felt ill the next day and self-isolated. She returned a negative test on Monday, but was moved to the Grand Mercure managed isolation facility in Wellington on Tuesday as a precaution.
Her second test came back positive yesterday. Her close contacts are isolating.
Later today we will be told more about the genomic sequencing.
If a clear link to the Defence Force cluster is confirmed, the next key piece in the jigsaw puzzle would be the number of links in the transmission chain between the Auckland student and the Defence Force workers.
Ideally there would be a direct link to the serviceman, which could mean there are no missing links in the infection chain.
Among the places he visited while potentially infectious is the Mezze Bar in downtown Auckland, which is around the corner from the A - Z Collection retail shop where the student worked.
CCTV footage is being studied, but so far there is no evidence of any interaction between them.
The other key question is how long the Government wants the quasi-lockdown to remain in the Auckland CBD.
Covid-19 can take up to two weeks to incubate, and people can be infectious for a few days before showing symptoms. If there are missing links in the transmission chain, the Government will be more inclined to continue the quasi-lockdown.
For how long?
It would depend on several factors such as the amount of testing happening now, the number of new cases popping up - including anyone in the Ubers that the student used, the Starbucks and restaurants she visited, and the Vincent Residences where she lives - and where they might have potentially spread the virus.
There are 100,000 workers in the CBD currently being told to keep their movements and contact to a minimum. They, and the rest of us, will be taking a keen interest in the genomic sequencing update this afternoon.