This is how it happened.
I remember Cameron Slater seething with frustration that John Key wouldn't talk to him.
He couldn't understand how Key was shielded, not because he was Prime Minister but because Slater was the blogger Whale Oil.
That was early 2012. In Dirty Politics, it is alleged that during the previous election, Slater was working with political adviser Simon Lusk to swing a National Party candidate selection to pick his man.
That was the Rodney electorate and his man was Mark Mitchell, the former dog handler turned private guard who enjoyed enthusiastic backing from Slater through his Whale Oil blog which highlighted only the negative aspects of his opponents.
Lusk and Slater wanted to step up their 'Candidates' College', at which they charged political aspirants for lessons on how to win in politics. They had a vision for the future. In February 2012, a document written by Simon Lusk charted out a plan to entrench the right-of-centre 'Fiscal Conservatives' for years to come. It involved "taking over the public service" and the "blackballing of current National MPs".
A month later, National Party board minutes show they saw the danger coming.
The minutes record "a disturbing conversation ... with Simon Lusk that highlighted his motivations and a very negative agenda for the party". His agenda posed a "serious risk to the party" and "light needs to be shed on these issues with key influencers within the party".
The Lusk and Slater duo was clearly seen as a danger - they aimed to hold another Candidates' College in April in the South Island.
But Slater couldn't get cut-through to see the Prime Minister.
It would all change in the next two years, and the way it changed reflected the willingness of those who could have stopped Slater to enable his behaviour instead.
At some point after April 2012, Key went from blocking Slater to talking and texting with the blogger, and posing for photographs at his side.
It was also about this time I stopped dealing with Slater.
Before then, as made clear in Nicky Hager's book, I was speaking to Slater as a contact and source.
We spoke regularly from 2010 until early to mid-2012. Generally, but not always, I would quote him as a source if I wrote something from information he gave me. I did this when he came to me with the Labour Party website security failure. I had no idea anybody from the National Party was meddling in the background - Slater presented it as his discovery and his alone.
Information has power. Those with the greatest access to information are those in power. Slater's links inside National meant he had access to good information.
But as 2012 got underway, I began to wonder who was manipulating Slater and whether I was in turn being made to do another's bidding.
It caused a feeling of great unease.
It's not unusual for journalists to deal with people who have causes to push, or axes to grind.
But when you can't see who, ultimately, is pushing the cause or grinding the axe, you risk failing yourself and your readership.
I had been in the tent. It was a place where stories and story tips came easily - too easily.
I stepped back and found myself outside the tent.
That, I think, is why Hager wrote: "They later fell out when Fisher wrote stories Slater did not like."
If you're in Slater's tent, it's warm and cosy. There is information which only those well connected would know. Almost exclusively, the tips are for stories are good for National and bad for anyone in its way.
If you're outside the tent, which is where I fetched up, it is cold and hard. This is what journalism should be. You should work for your readers, and work hard.
But when I started writing stories on issues which went against Slater's interests, I became someone he wanted to "smash". At that point, I was away from the tent and out in the wilderness.
He launched a personal assault with what I believed were threats of violence and created an atmosphere in which I was personally and professionally denigrated. Those who post comments on his website made awful slurs. It is as horrible an online environment as you will find anywhere.
Among the slurs were claims my behaviour showed I was suffering withdrawal symptoms associated with alcohol and drug addiction. On one occasion, when I rang a minister's spouse for comment on an issue he was involved in, he ranted at me that I was "a drug addict" and would not talk to me. The only place such an idea had been floated was on Slater's Twitter feed.
In almost two years, he has published about 120 posts in which I am featured. Some are extremely unpleasant. I am called a "shill" in the context of being a corrupt reporter.
Slater has invented nicknames for me. He called me "Gurnard", then sent me pictures of dead "Gurnard". He called me "Tainted" in relation to my coverage of the Kim Dotcom affair.
I've been accused of receiving stolen goods, had it suggested my performance at work was under question and had described sexual acts it is suggested might be inflicted upon me. I learned from reading posts about me that there is material on Whaleoil which is untrue, and much which so skewed it makes it difficult to discern what lies behind matters stated baldly as fact.
It is my opinon that Slater has cultivated on his blog such a nasty environment there can be no genuine benefit in dealing with him as a source.
I still interview Slater. When I do, he is courteous and gracious, giving time for questions and explaining his position in full. When I spoke to him a few days ago, he referred to me as an "ethical" journalist, and someone who was a "generous person".
I said to Slater: "You've called me ethical and generous in a conversation."
Slater: "Are you going to quote me? Are you going to quote me on that?"
I replied: "I might confuse your readers if I did that. They wouldn't believe I was actually speaking to you."
Slater said: "But remember there's a persona that's on a website and there's the persona of the person behind the website and they're two completely different things."
After two years of vicious abuse, Slater would have it that he wasn't really attacking me.
Instead, it was the mask he put on when he sat down at his keyboard.
He emailed after a story the other day, saying: "Time for all your emails to come out Fish".
It was my belief it was an attempt to dissuade me from reporting. When that was reported, he blogged: "Remember I still have my emails. Not sure David 'Tainted' Fisher is going to like those making their way public. Because the very thing he complains of in his stories he has participated in."
And, for a while, I did.
But once that feeling of unease came, I realised there would never be a story from Slater which was worth the cost.