I'm told there were six of them, and that they hunted as a pack. Their prey?
Delegates who had voted the wrong way.
Moving through the excited crowds at the Ellerslie Conference Centre last November, an angry group of Labour MPs was seen taking dissidents aside and telling them, in no uncertain terms, which way was up.
Leading the pack was Labour's employment relations spokeswoman, Darien Fenton, and her grim lieutenant, Dunedin South MP Clare Curran.
No surprises there. Ms Fenton and Ms Curran were among the caucus members most alarmed by the Labour Party rank-and-files' sudden outbreak of democratic distemper. The other members of the pack, however, came as a surprise.
I had never thought of Jacinda Ardern, Megan Woods, Kris Faafoi or Phil Twyford as attack dogs, but my sources assure me that they were there - chewing people out. So what?
Such brutal vignettes are the stock-and-trade of party conferences. Certainly "The Pack" was far from being the only example of caucus aggression at the Ellerslie conference.
It was Chris Hipkins who drew me aside long before the dramatic conference floor fight to murmur conspiratorially: "Our problems aren't external - they're internal." And Andrew Little, who first characterised the rank-and-file's bid to democratise their party as a statement of "anxiety" about the leader, David Shearer.
Even from the media table, the animosity directed towards caucus members who spoke in favour of the rank- and-file's resolutions (the most effective of whom, by far, was Leanne Dalziel) was unmistakable. Mr Hipkins' youthful countenance became an ugly mask of rage as he railed against the proposition that, to avoid a contest in Labour's new electoral college, the party leader must be endorsed by 60 per cent-plus-one of his caucus colleagues.
The underlying cause of all this angst was, of course, simple political arithmetic.
The first thing all politicians learn how to do is count and the people backing Mr Shearer were fearful that a democratised party (with sufficient support in caucus) might decide to wrest the power of choosing the party leader from their hands.
They were terrified that they would then be saddled with the rank-and-file's choice of December 2011: David Cunliffe. And it wasn't Mr Shearer's faction alone, who were counting heads.
Labour's deputy leader, Grant Robertson, had as much to fear from the leadership question being decided early, by the party, as his boss.
Now was the time for all who were not for Mr Cunliffe to unite against him.
MPs from both factions fanned out across the conference venue to dampen down and/or extinguish the dissident hot-spots.
The Parliamentary Press Gallery were encouraged to interpret the rank-and-file's attempt to "take back our party" as a leadership bid by Mr Shearer's rival.
The roving pack made up of Shearer and Robertson MPs would be joined by an even more vicious media pack led by TV3's Patrick Gower.
The rest is history.
On November 20, Mr Cunliffe is demoted and his faction isolated. On February 4, Mr Shearer manages - just - to secure the backing of 60 per cent-plus-one of his caucus colleagues. On February 19, six days before the long- awaited shadow cabinet reshuffle, Charles Chauvel, a supporter of Mr Cunliffe, quits Parliament.
On February 25, Mr Shearer's new lineup is announced. The Pack are well rewarded. Ms Fenton and Ms Curran both rise two places in the pecking order, while Mr Twyford goes up three to take a seat on the front bench.
Megan Woods enters the top 20 - a backbencher no longer.
Mr Little rises with her.
Mr Shearer's chief swordsman, Mr Hipkins, climbs five places to claim the shadow portfolio of education from Mr Cunliffe's running- mate, Nanaia Mahuta.
Ms Dalziel's eloquence on behalf of rank-and-file democracy is rewarded with demotion to the back benches.
Mr Cunliffe remains outside the magic circle. In Agatha Christie's Murder on the Orient Express all the suspects wielded the fatal knife.
Labour's MPs seem equally impressed by the advantages of collectivised bloodletting.
Trotter's piece explains the thinking behind David Shearer's reshuffle earlier this week. Loyalists have ascended in the rankings, whilst those loyal to Cunliffe have had the rug pulled from under them..
We're spending the weekend in Christchurch. We'll be especially interested to hear what our Christchurch friends and whanau think, given that Liane Dalziel, Labour's spokeswoman for the biggest ever single investment in this country's history ($30b and rising) sits in the lower third of Labour's rankings. Is that how Labour really wants to be seen in Christchurch, and is that the party's level of commitment to the rebuild?
It's a fascinating insight into the Labour Party mindset at the moment. How could a party wracked by such internal division ever hope to govern the country?