What's in the book?
Its full title is Hit & Run: The New Zealand SAS in Afghanistan and the meaning of honour. Central to the book is the now much-discussed NZSAS raid on August 22, 2010, in Baghlan province.
It describes the lead up to and execution of a raid called Operation Burnham by the NZSAS, which was stationed in Kabul at the time, on August 22, 2010.
It alleges the motivation of the raid was vengeance for the death two weeks earlier of Lieutenant Tim O'Donnell, who was based in Bamiyan province with the NZ Defence Force's Provincial Reconstruction Team.
Hit & Run claims the raid was botched and the NZSAS was responsible for the deaths of six civilians and the wounding of 15 others. The responsibility is sheeted home through the claim that the operation was conceived, planned, organised and overseen by the NZSAS.
It claimed that two of the dead were found with bullet wounds and the other four were killed by air support from United States Air Force Apache helicopters.
Further, it claims that the NZSAS deliberately torched houses in the villages that were the target of the raid and returned two weeks later to destroy more with explosives.
There's more. Other claims in the book are that the NZSAS continued to hunt O'Donnell's presumed killers and on catching one, beat him then handed him over to Afghan security forces with a reputation for torture. Other suspects were also hunted and killed.
Finally, Hit & Run claims this was followed by a deliberate cover-up with New Zealand Defence Force and politicians saying no civilians were killed.
And even when then-Defence Minister Jonathan Coleman conceded in 2014 that there were possible civilian casualties from air support, NZDF continued to say claims of civilian death were "unfounded".
It was New Zealand's fault, the book claimed, and an inquiry was needed to find out who had kept the truth from the public. The underlying issue is the question of war crimes - a very serious allegation.
Did we know any of this?
Yes and no. The raid was first revealed in 2011 by then-Defence Minister Wayne Mapp during a television interview. He was briefed on the raid and visiting NZDF personnel in Afghanistan at the time.
Mapp was asked if NZSAS was involved and confirmed it was, which TVNZ then reported along with its understanding 12 opposing combatants had been killed.
Asked about civilian casualties, he said that had "proven to be false". NZDF clarified shortly after saying nine "insurgents" had been killed and for the first time said reports of civilian casualties were "unfounded".
Have we heard from the villagers?
Hit & Run named those said to have died, had copies of their death certificates, photographs of those said to have been injured and interviews with those who claimed to have witnessed what occurred.
Then, three days after the book's release, lawyers came forward acting on behalf of the villagers to say their clients were seeking an inquiry into the allegations.
Where did this happen?
That has been a point of some controversy. Hit & Run said the raid was on two villages - Naik and Khak Khuday Dad - and included detailed maps showing where the villages were in Baghlan.
NZDF said it had never been to those villages, instead carrying out a raid on Tirgiran Village 2km away.
The villagers' lawyers appeared to correct both the authors and NZDF. They said there was no such village called "Tirgiran" and that was the name of the area - "Tirgiran Valley".
They say the villages of Naik and Khak Khuday Dad were exactly in the place NZDF had identified as its area of operations that day.
The authors then admitted the maps in the book had placed the villages in the wrong place, marking them on a nearby area, which had broadly the same geography. Honest mistake, they said.
Does the confusion over location matter?
There seems to be little doubt the authors and NZDF are talking about the same event. There are enough common details to match the events in Hit & Run to the NZDF's account this week. Those events also matched details from a NZSAS soldier spoken to by the Herald.
But it does matter because the inaccuracy damages the credibility of the book. It wasn't just mislabelling one area as another - the authors circled and painstakingly named houses belong to those they said were victims, apparently from interviews.
It has raised the question since: 'If they got the location of the villages wrong, what else should be questioned"?
Where did those initial claims of civilian casualties come from?
Although New Zealand's involvement was not yet known, the New York Times quoted local officials as saying there were eight civilians killed and 12 wounded.
The governor of the province, Mohammed Ismail, said six of the dead were found in the village of Naik and two others in fields away from the village. Also quoted was Ahmad Shah, a resident of Naik, who reported helicopters and gunfire.
The International Security Assistance Force - the umbrella group for the 60 or so countries in coalition - said on August 23, 2010, "no civilians were injured or killed" and that 12 "insurgents" had been killed.
Then, six days later, it said an investigation had been carried out and there were possible "civilian casualties" due to a malfunctioning gun sight on one of the Apache helicopters. It also said there were 13 "insurgents" killed.
What do we know about the ISAF investigation?
It was carried out alongside two Afghan government ministries. We know no one visited the scene of the raid. Instead, reviewers read operational briefings, meet Mohammed Ismail and review weapons-system video. The report on the raid has not been released.
The Chief of the Defence Force said he had read the summary but that NZDF does not have a copy of the investigation.
And what does NZDF say to all of this?
After almost a week's silence, Chief of Defence Lieutenant-General Tim Keating called a press conference to deny the NZSAS had killed civilians. Keating's initial focus was on the discrepancy in location, saying the NZSAS had never operated in the place the book claimed it had.
But he then added details that appeared to confirm some of the actions described in the book.
Keating said a New Zealand soldier had killed one person. He also said a New Zealander had directed the air support for the raid, adding that it had been moderated with a view to protecting non-combatants, including children.
Keating also said that revenge was not a factor and that the mission had been carefully reviewed by a lawyer before it happened. He called for any witnesses who had information to share to come forward.
Keating also stepped back from NZDF's six-year statement that claims of civilian casualties were "unfounded", saying it was possible innocents had been killed.
What about the authors?
Nicky Hager and Jon Stephenson are polarising figures. Hager's previous books, which include detailed accounts of the work of intelligence agencies and the military, have created a fan club but also an angry mob.
Detractors say he delivers books in election years to target governments he doesn't like.
Stephenson has long operated as a freelance journalist in war zones and comes to Hit & Run having sued NZDF over four years for saying he made up aspects of an award-winning 2011 Metro article alleging the NZSAS were complicit in human rights abuses. NZDF settled with Stephenson and apologised.
Don't civilians always get caught up in war?
In Afghanistan, it is estimated about 25,000 civilians have been killed since the United States invaded in 2001. Much of that comes back to the US Air Force but there was also concern raised about the time of Operation Burnham over collateral damage in special forces night raids.
The complicating factor in Afghanistan is that combatants can become civilians simply by putting down a weapon. In this case, there would be no question the 3-year-old Fatima said to have been killed was a non-combatant.
Will there be an inquiry?
It's highly likely. At its essence, there is a key difference between the claims in the book Hit & Run and NZDF's position. Hit & Run says six civilians were killed, including a 3-year-old girl. NZDF says nine combatants were killed.
But the high likelihood of an inquiry stems from the involvement of the lawyers, Rodney Harrison, QC, Deborah Manning and Richard McLeod. New Zealand is signatory to international laws, which dovetail into our legislation, that are likely to give them the power to force NZDF into court.
At this stage, they are seeking a Commission of Inquiry with three commissioners, one of whom they say should be a senior judge. Mapp said yesterday "as a nation we owe it to ourselves to find out" and to front up.
What are the possible outcomes?
Compensation was said by Mapp to be appropriate under Afghan culture. However, the allegation of "war crimes", if true, comes with significant penalties, including life in prison.
The Hit & Run authors also called for an end to the secrecy under which the NZSAS is able to operate. Further, they say former NZSAS commanders have gone on to senior roles in the military, creating an imbalance of power and a tendency to lobby for international duties that meet their skillset.
There are no set dates in terms of decisions being made about next steps.