So they made their way through the cave and so enter the redbrand hideout by semi unconventional means, seeing before them a large semi natural cave they are at the south end of, with a chasm from south to north through it's floor and they on the west side of that chasm. A pair of bridges cross it and a pair of natural stone columns support the ceiling. And something not quite human lurks behind the closest column.
Well, it they look closer and it's a man sized creature with one massive eye. At that point it starts speaking into their minds "What are you doing here?"
Now the responce - it seems a little meta. A little fourth wall breaking. A little deadpool. They say they live here now.
I mean, who says that straightfaced in real life? But if you're half out of character because you're half in the meta, then why not? But in real life it's actually a little lunatic to say that with a straight face/conviction.
On the other hand they don't just discard the idea of negotiation (in favour of, say, hacking anything not them to bits). Even when the paladin detects it as evil (which, I try to explain, doesn't mean it's somehow right to kill it - though it does mean it's probably a jerk and a douche)
The rogue decides to rush up and...spread marbles!
I think he expect it to be dazzled by shiny objects as it's a monster - now I haven't checked, but I'm wondering if the creature actually has a higher INT score than the rogue.
In responce it reads his mind for a dark secret - so I prompt the player to describe his background that he said was detailed. I may not recall correctly, but I think at first there was something about wanting to be the best baker in town...and really, is that a dark secret?
So I push some more...and some more...and I get something about him having killed his rival!? Whoa! Paydirt! There's a sudden, juicy chunk of meat on the table!
"Ah, my little marble murderer! Such a delight you are!" the creature (a Nothic) whispers into his mind.
Someone just made a friend!
Well to be fair it wanted food and even though they were practically still in town and could buy food, they decided to hunt anyway - catching several rabbits as the passing roll has it. Which they offered to the creature who took them happily. With that, they began to examine the exiting passages from the cave and make their choice...
But that marble murderer moment would tie in in a perverse poetic justice latter on...