Last week was the best Labour has had this year - until Thursday.
It had the Government on the ropes over the wage gap with Australia, there was intense media focus on Cabinet's refusal to lower the drink-drive alcohol limit, and employment law changes were drawing fire.
Chris Carter changed all that. In just one day he managed to create more mayhem than Labour has had to deal with since the election.
The MP's actions were weird on so many fronts, yet he has created the potential for the one of the worst things that can happen to a party - doubts about its leader's abilities and the possibility of a caucus coup.
However unlikely that may be, it is extremely de-stabilising and distracting and the longer it goes on the worse it becomes.
MPs find they can't get any traction on anything else because the media is obsessed with it, and eventually they start wondering whether the effort is worth it.
That is why Goff and his senior MPs are trying so hard to shut this down. They know they have to, because if they don't the whole thing will unravel.
Carter says he was motivated to send his anonymous letter to the media by his belief, which he claims is shared by other caucus members, that Labour can't win next year's election with Goff as leader.
His reasons are open to question, and it is difficult not to think his actions were an embittered response to Goff's disciplinary action against him over ministerial spending and the removal of his treasured foreign affairs portfolio.
Assuming his stated reasons were valid, then he must believe there is someone else who can win the next election. If so, who? In an oblique way he mentioned David Cunliffe, who subsequently declared his "100 percent" support for Goff and said he wasn't going to challenge him.
The reality is that Labour's chances of winning are virtually zero, regardless of who leads the party.
The last three governments have all run for three terms. The present government, midway through its first term, is extraordinarly popular. Prime Minister John Key is extraordinarily popular.
Unless something catastrophic happens, nothing short of divine intervention is going to put Labour back in power next year.
It wouldn't make much sense for Cunliffe, who is far from stupid, to challenge for the leadership ahead of an election he must know he would lose, even if he wouldn't ever acknowledge it.
The next weird thing is that if Carter was trying to foment rebellion in the ranks, which he admitted he was, why disclose information about trouble brewing which was going to come to a head at this week's caucus meeting?
By doing so he made sure the party leadership could stop it happening and that the ranks would close around Goff in a damage control exercise which transcends any doubts MPs might have about the leader's effectiveness.
Then there is his justification for the underhand tactics he employed. It was "the way things are done in politics" he explained.
It isn't. The way things are done is for disaffected caucus members to work very quietly to consolidate opposition to the leader and try to reach the point where there are enough signatures on a piece of paper to present a fait accompli.
Sometimes they don't manage to do it quietly enough and all hell breaks loose, but it is totally counter-productive for one MP to try to go it alone.
Labour doesn't need to change its leader and the very worst thing would be for it to start to panic over its poll ratings. Those ratings aren't that bad, and were actually starting to improve.
Against a popular government, Labour is holding its vote at around election night level and could have expected it to improve as the Government deals with an increasing number of difficult issues.
Carter may have reversed that trend - nothing turns voters off more than a party that can't hold itself together and National knows it. Key has already put that into words, asking how Labour could be trusted to run the country when it can't run itself.
If there is any benefit to be gained from all this, Goff has made a good effort at achieving it. He moved quickly and decisively, removing Carter from caucus on a unanimous vote within hours of the culprit being identified.
In contrast, party president Andrew Little doesn't seem to have perceived the need to deal with Carter as quickly as possible.
The next move is for Carter to be expelled from the party, cutting all its ties with him, making him an independent MP.
Little's reaction was to say there was a meeting of Labour's council scheduled for Saturday and it would be dealt with then.
He should have convened the council on Friday and expelled Carter, instead there is going to be a week of anticipation and Little says there is a range of options "the worst of which is expulsion".
While he does have to grant due process and Carter must he given a hearing, because Goff has said the MP will be expelled anything short of that would be a vote of no confidence in the party leader. Goff would have to resign, and then the caucus would be really be in crisis.
Whether this debacle has a lasting impact on Labour depends largely on whether Carter keeps quiet or continues to fuel the fire he has ignited.
If he fades away as a lonely independent MP, which is the most likely outcome because the media will eventually stop taking any notice of him, the party will recover.
Even so, as National discovered when Maurice Williamson attacked his then leader Bill English back in the days when the party was in opposition, recovery can be long and painful.
