The police do not know who did it, the prime minister has a theory but will not say what it is, and the victim says he accepts the culprit probably will not ever be found.
The last chapter in the saga of Don Brash's stolen emails has been closed with the release of a police report into a review of how it handled the case, and no one is any the wiser.
It began with the publication in November 2006 of the explosive book The Hollow Men, written by researcher Nicky Hager and based on 475 emails to and from Brash, and other political players, which detailed the sometimes tawdry tales behind National's 2005 election campaign.
Brash resigned as party leader in the same month, and the police began trying to find out how Hager got hold of the emails.
They could not, and did not even discover whether the parliamentary server had been hacked, although they thought that unlikely.
Brash complained of political bias - Labour was in power at the time - so the police re-investigated the case.
After interviewing 199 people, they confirmed the original findings - the emails were taken over an extended period of time although they did not know how or by whom, security was lax in Brash's parliamentary office and its surroundings, and Brash sometimes printed out emails and left them in a tray to be shredded.
There is no evidence of political bias, although it is acknowledged Brash should have been kept in the loop and a promise has been made to handle politically sensitive cases differently in future.
One new morsel is that Brash may have used an auto forward function on his email accounts which duplicated them to a non-secure network over the internet.
Asked about all this on Monday Prime Minister John Key, who replaced Brash as leader of the National Party, intrigued journalists by saying he believes a hacker had been at work and he had a theory about who it was.
That was as far as he was prepared to go, although he did say rumours at the time about senior National Party figures being behind it was "bollocks".
"I think the computer system was hacked into," says Key.
"That's where I believe the leak was. But I can't back it up."
Asked whether he had a theory about who did the hacking, he replied: "Yes I do actually. But I don't know."
Key says it seems the case is going to sit in the category of unsolved mysteries.
Brash appears to agree. He has accepted the review report, has no further complaints about the case, and does not believe the person or persons responsible will ever be identified.
