I've been working this for a while, and seem stuck, so I'll post this in the hope someone else can find the next step.
This could be part of the notorious Battle Staff quest, or perhaps something else.
This was apparently broken for many years, until the Highpass Roses were put in the game (fished in Highpass).
Hand Lady McCabe Highpass Roses and Drom's Champagne and a script is triggered.
Lady McCabe says, 'Mmmm... Yes. It all looks sooo delicious! I do believe the temperature just raised a little. Maybe I should slip into something more comfortable...'
Your faction standing with Highpass Guards could not possibly get any better.
Your faction standing with Carson McCabe has been adjusted by 1.
Your faction standing with Merchants of Highpass has been adjusted by 1.
Your faction standing with Corrupt Qeynos Guards has been adjusted by 1.
Your faction standing with The Freeport Militia has been adjusted by 1.
You gain experience!
(Carson spawns in the room)
*Carson McCabe says, 'What is going on here?! Who is this?!'
Lady McCabe says, 'Oh, dear! How good to see you! This is merely my new jester whom I sent to... umm... to the cellars to fetch me some champagne. I was going to surprise you.'
*Carson McCabe says, 'Hmmph! Well. I am busy right now. I must go to... uuuh... To check on the prisoners. Pardons you know. Noggin! Noggin, stay here and make sure no one bothers Lady McCabe. I must be going.'
Carson walks away and despawns after a minute or two. This version doesn't say anything different than the normal one. He also doesn't drop anything special (I took the massive faction hit so you don't have to..)
You say, 'who is noggin?'
Lady McCabe says, 'Noggin is Carson's personal bodyguard. He doesn't talk since Carson cut his tongue out.'
When I first found this, Noggin spawned after Carson and after a few minutes, walked off and despawned. Now, I no longer see Noggin. (He was an Ogre, if I recall correctly.) I don't think I successfully hailed him - with no tongue, he might not be talking.
Good luck working this 22 year (and counting) old mystery!