Okay haha no she's not stupid enough not to think that they'd hold her in such disregard as to leave her conscious and unparalyzed just to show Hellish contempt; it'd be an unnecessary risk.

...Detect Thoughts.  They've left her alone to see if she thinks anything interesting once she thinks she's alone.

She has 6 less WIS than usual and her core is hollow and empty; if anything that almost saves her, that her INT is collapsed along with her WIS, and that there's so much more internal suffering to distract her.  Her mind literally fails to prioritize all the things that she'd least want Keltham and Carissa to know, just like she had trouble prioritizing for her custodian devil any thoughts like 'this might just be the first stage of Keltham's plan'.

Well, what shouldn't she be thinking, right now -

She absolutely shouldn't be thinking that question.  Obviously.

Ha.  If she was Carissa, she'd already be thinking exactly the thoughts that would be advantageous for her captors to observe her thinking -

Okay THAT was not a smart thought to think while Carissa was possibly reading her mind and maybe being reminded of some things to possibly get angry about.

Abrogail Thrune humbly acknowledges that Carissa Sevar is much better at this important life skill, which Abrogail, in her spoilation, has not had due chance to practice after she took the throne.

Standard advice about beating Detect Thoughts - during that transient pleasant interlude while your captors haven't yet gotten around to torturing you until your will is broken, or also cursing you with -12 WIS so you have a four-year-old's self-control - is that you find something to think about, rather than not think about.  It's fine if it's something horribly fascinating.  And in the back of your mind, you have something else to not think about which is not as ruinous - Abrogail's passwords, maybe, such as a would-be Queen might need - actually she does not want to share that with Carissa either.

That time she noticed that some part of herself was glad that Carissa was having fun.

There's a thing to try not to think about.

Or tropes - not thinking of any hopes where the audience might watch her thoughts - she has some practice in not thinking that.  So she can carefully not think any tropey hopes, even while trying to focus her actual thoughts - on -

The two times she's had sex with Carissa?  Would that make Keltham jealous, or aroused, or angry, would he take revenge on her in - in a useful way, in a way that means she wins - no she shouldn't think that, it decreases the chance that Keltham -

How strange, she actually does not want him doing that to her, breaking her pride as a woman, not even if it's useful.  She would have thought that it would be a more sexual thought than that, to her, being wholly overcome by a man.  Maybe it's the aching hole in her Splendour, that it takes stronger feelings to be that more interesting Abrogail.

Well.  If she really would hate it, that definitely increases the chance he'll bother to humiliate her, if the boy has gained any manhood at all.

Romance novel tropes -

Surely she cannot be taken, subdued, conquered, this easily, this cannot be the end for her, just like this, it lacks drama -

(That's a hopeful thought, Aspexia has forbidden her to think those -)

No!  No it's safe to think that.  It's a vague hope - and Keltham or Carissa or both are reading her mind, and now their character viewpoints matter - if she thinks 'it can't end for me with this little drama' and they believe it's the end for her based on their specific plans and this is true, that doesn't fly as drama.

Something unexpected would happen from their standpoint, something would shake up the story -

She waits, then, her body tense, now that she can move any muscle at all.

Obviously and as any sane person would expect, nothing happens.

When her lungs start to hurt, she realizes she was unconsciously holding her breath and lets it out.

There's a rumbling cold chuckle, and then a pit fiend - the same pit fiend who was leaning over her before, as you can recognize if you've had enough dealings with devils - leans over Abrogail once more, and picks her up much as Keltham did, though with far greater Strength.

...it is possible, it is imaginable, that the lesser Carissa Sevar within Dis might have failed to negotiate any explicit compact-term along the lines of 'When I use my Gate back, the pit fiends are not allowed to follow me, invisibly or otherwise.'  It is not the sort of thing you'd imagine a pit fiend to bother doing, if it wasn't an effortless cruel-prank to play while you were right there.  Or the lesser Carissa might imaginably have thought - especially if she feared her own true loyalties - that a faithful subject of Asmodeus ought not want to impede a pit fiend, if something mattered that much to Hell's third tier of nobility.

Hell does like its little games, you could say, especially when it comes to granting Wishes that are the least bit interesting.

HAHAHA YES SHE DID IT, SHE FINALLY DID IT, SHE DID A TROPE

no that's definitely a bad thought, that's hope, now what terrible thing happens to her as a result of thinking that, also why is she worth a pit fiend's trouble to rescue -

Abrogail knows the answer almost as soon as she thinks the question.  This isn't about her.

The pit fiend turns to where Keltham now stands visible, rumbles in Taldane, "Where is the Crown of Infernal Majesty?"  It doesn't add any threats, possibly because threats are a superfluous part of speech when the sentence is spoken by a pit fiend.

Keltham replies to it in Infernal with unchanging expression.  "You stand on territory governed by compact recorded by the erinyes Lrilatha, between Keltham of Elsewhere, and Asmodeus the Prince of Hell, and Otolmens the Preserver of Creation."

He is holding up a sheet of parchment inscribed with ornate Infernal letters.  Abrogail can hardly crane her neck to see it, and she is no longer smart enough to memorize the contents at a glance if she could.

"I am forbidden to take from this place what is yours," the pit fiend's voice replies in that same language.  "What you win from mortals and devils may be yours, but this sold itself to Asmodeus, and is Asmodeus's.  I so rule."

"This is a matter between myself and two gods, and neither I nor They designate you as arbiter in how Asmodeus's part governs you."

The pit fiend's voice deepens; there is a tangible power to it, when it speaks.  "And yet I am taking this back to Hell, and that is reality, and there is no meaning for you in considering any other possibility."

"Then perhaps I shall leave this place, and tell Lrilatha why, so that Asmodeus can explain to Otolmens how and by who Their ongoing compact with me was broken, as I judge it."

"Where is the Crown of Infernal Majesty?"

"In a safe place.  I, who was cleric of Abadar, had meant to offer that Crown to Hell at a fair price; to that price I will add the return of what you now take, and a penalty."

"The price of disrespect will be extracted from you in due time."  The pit fiend with its power strong about it pulls the cursed crown from Abrogail's head, the magic yielding without visible effort to it; pulls the cursed amulet from over her neck without damaging it, strips the chains from her and also the tiny sword woven into her hair; and drops them upon the ground.  "Here is all that is yours."

"Placing her where she could be retrieved by me, after a ruling by an agreed arbiter, would guard against Asmodeus being irrevocably foresworn to the god who guards all Creation."

The pit fiend does not dignify this with an answer, but turns and strides out of the Forbiddance Abrogail was brought inside, to the edge of the demiplane.

There's the sensation of the pit fiend plane shifting, then plane shifting again, followed by the sensation of an ordinary Teleport.

Abrogail does not know where in Dis she has been brought, but it is easily recognized as a fortress of Dis to anyone who has traveled there.

The pit fiend hands her over to a lesser devil that guards the gate, of that fortress; if there are instructions spoken they are conveyed telepathically and not for mortal ears to hear.

...this is probably, still, on net, a good thing; the pit in her stomach has fallen only half as deep, now.  She doesn't know what Keltham wanted of her, and he might be able to buy a disgraced Queen with the Crown; she is not escaped from his grasp, if she matters to some plan of his.  But whatever is to follow, Hell has much more of an interest in Abrogail Thrune still being Queen of Cheliax when it's over.  They'll extract a price in pain, for her failure; but pain is something she knows how to bear, even if it can't be borne, you just go on.