Then they'll put through the Greater Scry.

Keltham appears within the mirror, glances at the apparent camera location, and casts from scroll a Greater Scry of his own.  His eyes within the mirror focus then on the two devils, and don't particularly seem to see Abrogail - not in the fashion of ignoring her, but in the fashion of Abrogail not being visible to his scry at all.

"Is the living mortal Abrogail Thrune II, who was born to that name and compacted with the god Asmodeus and once signed a compact with myself, present nearby and ready imminently to be interrogated by you, in accordance with that agreement made between myself and Hell one hour and thirteen minutes earlier in the mortal realm?"

...there's only stars and blackness visible behind him, in the mirror, in the scry radius around him; and there's something wrong with those stars, they are too many and too bright in the blackness for him to be standing silhouetted against ordinary night.

"Yes," says the devil, bored.

With enough INT and WIS she sees those too-bright stars and makes the connection, where Keltham must be, what must be below him, and her heart almost stops; she knows then, she knows the question which Keltham is going to ask of Hell, and why he expects that Hell might answer, and she knows he'll demand they read her thoughts and swear to it -

"I plan to ascend to godhood shortly, and expect to succeed about that plan.  I am checking whether there exists a mess in the mortal realm that I need to clean up first."

"If the matter I speak of is not resolved to me with surety, I will use knowledge out of Elsewhere to utterly destroy the entire territory of Cheliax, as my default action in ignorance; as I would have done simply to be sure, had there been no way whatsoever to confirm the matter from Abrogail Thrune or Hell.  You are now being offered an opportunity for an outcome which is not that."

"The blood of dath ilan is adept at finding creative paths to destruction, in a way not fully captured by measurement spells for Intelligence and Wisdom and Splendour.  If anyone has stolen children from me, they will when grown present some additional danger to the continued existence of Golarion and perhaps larger regions than that."

"I suspected Cheliax of having stolen children from me by way of substitution plots of Abrogail Thrune, Willa Shilira, and Jacint Subirachs, all of whom I have already slain.  I am concerned that perhaps more children than that have been stolen from me."

"If Asmodeus's instructions sent by vision to Ferrer Maillol, not to take hostages against me, have been obeyed diligently rather than cleverly and dancing around the edges, those instructions interpreted generously should have covered that contingency, for any child of mine permitted to be ensouled might be hostage against me.  I have taken Maillol and read his thoughts under interrogation and confirmed that this would be in the uncertain edges of Asmodeus's instructions; more hopefully, from my perspective, he recalls no such question being asked of him, as any sensible person would surely have done.  However he also recalls his mind being read by Carissa, and I cannot rule out the event that he was asked this question and then had his memory erased about it.  Nor, for that matter, can I rule out that Abrogail was enough of an idiot to not ask him, or to dance around the edges of Asmodeus's instructions, as she certainly did with respect to many other potential hostages that she claimed were not really hostages."

"I therefore ask you to read the mind of Abrogail Thrune and confirm to me that I have no children of Cheliax remaining and known to her nor in the least bit suspected by her, now that she, Willa, and Jacint have been killed.  Or, if there were other children stolen of me, I would have Hell and Cheliax swear satisfactory oaths to see all pregnancies ended swiftly before they can be ensouled.  I will pay for costs incurred there, as a salve to Hell's pride, though it would be greatly in your interest to do so even if I paid nothing."

"I will see this matter on an oath-assured path toward satisfactory resolution, or else burn all Cheliax to ash, before this scry ends."  Keltham holds up a lesser mirror to the scry-node, angling it so that it shows the land of Cheliax far far below him, upon the curve of Golarion where it floats in space.

no no no no no NO NO NO NO

"If we are inclined to give you this assurance, we will do so before this scry ends," the devil says, and turns to Abrogail, looking, now, substantially less bored. "Have you assurances of interest to this Keltham, your majesty?" The title is, of course, mockery; they weren't using it when they thought she was the Queen of a powerful and capable Cheliax.

"I have not -"

"I am unassured by her words and only satisfied by what you swear in Asmodeus's name were her thoughts."

Her thoughts?  She tries to bend them, of course she does, she has never given Keltham any children other than the one she held within herself, now slain by him before it could be ensouled -

(Scattered his children wide, priestesses and wizards and noblewomen; a few where not even Church or Crown knew where to find them, peasant women taken anonymously and returned anonymously and told to keep silence, and some of those beyond Cheliax's borders -)

"Do the means exist to identify all those in Cheliax, or all those in any specific duchy of it; or who would that question be asked, if not you."

Yes, of course, they kept records -

(But not complete records, for they wished to ensure that the story would be irrevocably a tragedy according to dath ilani tropes, so that having ensured a dath-ilan-unhappy ending they could then work further to make it the specific kind of dath-ilan-unhappy they wanted; they tried to make it impossible for Keltham to retrieve all his children no matter how hard he tried, impossible even for Cheliax to retrieve them, leaving no pathway or possible twist of the story by which it would all have a dath-ilan-happy ending after all -)

"Who kept the records?"

The task was delegated to a fifth-circle of Asmodeus by herself and Aspexia; records would be within the Palace Forbiddance in Egorian, probably in a section that deals in secret project records.

(nothing written down or recorded about the extra babies, they weren't that stupid)

(doesn't think about how Aspexia Rugatonn thought it was fine, because there are no excuses, no defenses, but there sure is a pre-thought about how that is a defense she's not trying to offer Hell)

Then the devil will state to Keltham, that Abrogail has thought of a secret project, for which records are contained within the palace in Egorian, and that Hell will accept Keltham's payment for their trouble in pursuing every woman in those records, and ensuring that his children never come to be. 

"You did not swear that Abrogail Thrune expected there to be no child of my blood unknown to me, that is not recorded in those records."

"You did not swear that these were her thoughts that she thought to be true, rather than thoughts that she thought deliberately."

"You did not swear that she had no other thoughts that negated those you described to me."

"Unless you have far better cards in your hand than those, you do not have the option-resources to trick me about this.  That wouldn't have worked on an INT 29 four-year-old.  The deception you tried was one that I'd visualized in toto as a possibility before I contacted Hell to open negotiations; it corresponds to a class of scenarios where I have some children in those records and some unrecorded children."

"Is there another set of records to trace those other children?  Unwritten memories of them?  Near-deterministic procedures that could be re-run to reproduce trajectories from a small set of possibilities?  I would like to not destroy Cheliax, here.  What exactly has Cheliax done, and is there any way it could be salvaged if we all cooperate?  Even if you cannot think of one, perhaps I can."

"There are some children not in the records, and some of them outside of Cheliax entirely. You will have to destroy all of Golarion, if this is how you are so moved to act. Hell will gladly receive them; people often repent, in their old age, so calamity is not often our enemy."

Keltham's face doesn't change expression.  "If I destroy Cheliax, some people go to Hell today, fewer people go to Hell later, my later dealings with Asmodeus are more fraught, and I'd need to delay to do something about the Worldwound once Cheliax can't help fight it and the Worldwound isn't needed to occupy Cheliax.  I've already had this argument with Carissa Sevar and she's smarter than you and has more complete information."

"My function for whether it's worth destroying Cheliax to destroy some number of unrecorded children there, given that I have a second number of untraceable children outside it, is a complicated one.  Tell me those two numbers straight.  Tell me the complete details on what Abrogail Thrune has done, in case I can think of a solution not apparent to the devils containing this negotiating-information."

Then the devil will turn to Abrogail, and ask these numbers.

She, herself does not know the exact numbers; unreported is unreported.  Based on - the broad orders she gave, the resources she assigned - there should be around five times as many children within Cheliax as without; and the fourth part of Keltham's 144 children will have gone unrecorded.  She - did say that there should be exactly 144 at the end, because tropes and irony, so - the officers that she designated to do this, should be able to reconstruct the exact numbers inside and outside Cheliax, if asked - probably - though there were three Modify Memory scrolls that she designated to be used, there.

This the devil will report, this time adding that Abrogail Thrune II did not think thoughts contrary to these, and that she believed what she thought was true.

His expression does flicker, barely, when it's said that he was to be given exactly 144 children.

"I'd speak to Abrogail Thrune directly, with her words made meaningful by your prior assurance that you'll speak out if her thoughts contradict her spoken words.  Perhaps she'll have something unforeseen to say that implies I should not destroy Cheliax."

"There is a thresholded binary outcome here and it is not presently leaning favorable to you; you should seek to expose me to complicated unknowns that stand a chance of changing that outcome, even if you cannot foresee their exact impacts, so long as they do not seem net negative in the presence of other unknown unknowns that might also save you.  If that goes against the grain of a devil who seeks predictable paths, we may negotiate whether you could bind a superior devil to the secrecy and information-nonuse conditions, and ask them for authorization; this is not the right time for the narrowly-thinking way that the lesser ranks of Hell deal with uncertainty."

And does Abrogail Thrune, with this assurance made, have anything to say for herself?

If she knew words to dissuade this Keltham from this path, she would have thought them at the devil already!  There are no brilliant strategems in her, that might outface this Keltham. Only horror and sickness in her that she cannot recall ever having felt, for never in her entire life has her future looked this dark.

Abrogail Thrune considers, as very few other people in Cheliax would even think to consider, telling Keltham that she's sorry; Abrogail has met more foreigners than the average Chelish citizen.  But she does not foresee it ending well for her, it wasn't like she injured Keltham by accident and regrets the harm to him, as might lead one non-Asmodean to forgive another.  She sincerely regrets the harm to herself, to her interests, maybe even to Cheliax; her feelings toward Keltham are poisonous hate and horror.

She considers begging, groveling - it wouldn't help, is the thing, even if he wants to see it, he wants to see it and then he wants to see her anguish as Cheliax is destroyed, in those cases.  Or should she try it, even if she doesn't expect it to work, because it's not sure?  Is that the message he was giving her, when he spoke it to a devil before her?  If so, she will do it, because - people often want vindication, the proof of their triumph and rightness and superiority, and it's worth gambling on the tiny chance he'd be satisfied -

"If you want me to beg, grovel, I will, and mean it, the only reason I'm not already is that I'm not sure what you want and I don't want to annoy you instead," Abrogail says.  Her face shows the real horror, her voice bears the anguish that's there.  It's not a familiar mode of thought, to her, but she does know what torturers look for in a victim.

"Why did you do that?  The actual cause and reason."