Labelled the November quarantine cluster by the Ministry of Health, it began when a Defence Force worker, known as Case A, at Auckland's Jet Park quarantine facility tested positive earlier this month.
Within the space of a fortnight six people in Auckland and Wellington have become infected. But exactly how all the Covid-positive people contracted the virus remains a mystery.
On November 8, the public learned a close contact of Case A had contracted the deadly virus.
Referred to as Case B, it was later confirmed that person was also a Defence Force employee.
The Ministry of Health said while Case B did not work with Case A at the Jet Park quarantine facility, he was at a work-related meeting on November 4 in Auckland before travelling home to Wellington.
All those who attended the same meeting had been identified and were self-isolating as a precaution.
Case B was transferred to a quarantine facility in Wellington and five household contacts went into self-isolation.
Alarm was sparked by Case B's movements after flying on Air New Zealand flight NZ 457 between Auckland and Wellington on Thursday, November 5. He did not wear a mask.
Passengers seated two seats in all directions were contacted and asked to get tested and self-isolate until November 19.
As an added precaution, health officials asked households of those on the flight to isolate until advised that their flight close contact had had a negative result.
Case B reported developing mild symptoms late the next day. They had three household contacts - all of whom tested negative.
The contacts included two young children who attended two different schools, Boulcott Primary and Hutt Intermediate, in Lower Hutt.
The children were put into isolation and returned a negative test after day three.
The students had been off school on Friday, November 6 - the day the Defence Force worker started showing symptoms - and as a precaution, remained in isolation for 14 days.
Genome sequencing matched Case A and B, confirming transmission of Covid-19 from the first Defence Force staffer to the second.
Second Wellington case
Then last week, on Thursday, a new case emerged - Case C. It was found that person was a close contact of Case B and tested positive on the day before, on November 11.
That person met Case B for lunch in Wellington at the Little Penang restaurant on The Terrace on Friday afternoon. On developing symptoms on Saturday they self-isolated at home and had a Covid-19 test.
Although initially returning a negative result on day three, they were moved to quarantine at the Grand Mercure in Wellington as a precaution. A second test confirmed a positive result.
AUT student
Then it emerged an AUT student (Case D) aged in her 20s who works at the A-Z Collections store in downtown Auckland, tested positive.
She was genomically linked to the original Defence Force worker who was infected at the quarantine hotel but it's not yet clear how the pair came into contact.
She works just 82m from a cafe the defence worker visited.
Auckland CBD workers were asked to work from home after a long list of places the woman had visited was released.
There was also confusion about whether the woman was told to go to work after becoming sick.
Last Thursday director of public health Dr Caroline McElnay jointly fronted a press conference with Covid Response Minister Chris Hipkins, and said the woman called in sick to work after being tested, but ended up working after talking to her manager, but wore a mask.
However, A-Z Collections owners, husband and wife Bing Wang and Mei Chen, have since issued a statement via their lawyers, Focus Law, claiming the employee had never told them she was sick, sought to call in sick, or that she'd had a Covid test.
The Herald has been unable to speak to the student directly. Focus Law released a statement from her, saying on the evening of Monday, November 9 she had a sore throat, and contacted her GP the next day, and they recommended a Covid test.
On Wednesday, November 11, her sore throat had gone, the statement read, and she went to work, wearing a mask "just to be safe".
"I did not tell my boss or manager of the above and did not request leave at any time. I did not think it was a big deal."
According to the statement, language barrier issues meant ARPHS staff "made many errors in recording my previous whereabouts, actions and contacts".
Officials then arranged for a translator to assist contact tracers.
A person (Case E) who lives in the same apartment building as the Auckland student then tested positive for Covid-19.
Latest case
Officially dubbed Case F by health authorities, the person is a border worker in Wellington and a close contact of the second Defence Force staff member.
Saturday's case is one of 55 close contacts of Case B and had been self-isolating at home since the first week of November.
Last Wednesday, however, they chose to go into a dedicated managed isolation facility in Wellington and where they remain still after testing positive for coronavirus.