"Who knows about the gate? Who knows where it opens?" How can we give Abrogail an alternative explanation for how this information fell into enemy hands?

That's the problem, isn't it. The plans to Wishnap the little bitch failed, and now Abrogail's being careful. "Myself, Lrilatha, Gorthoklek, Rugatonn. If Rugatonn brought in anyone else in the church she wouldn't have told me." 

"Hmmm. Any of them planning to come out of their hidey-holes? Is Gorthoklek planning to lead any armies in the field?"

"He is, yes. If it goes poorly, well, once there's a Gate through which the forces of Hell come to our defense it's not that costly to send another pit fiend." She would really have expected 'a permanent Gate through which the forces of Hell come to our defense' to be, itself, too costly, but she never really understood the rules the gods played their little game with the world by.

"How soon?"

"Before the invaders get out of the mountains."

"Soon, then."

"They're terrified. And shocked. We were prepared to fight Andoran this spring, and prepared for Cyprian to sweep in once we were winning that one. Lastwall gave a very compelling impression of being - overstretched and out of options -"

"Clearly they weren't."

A solid wall of hellfire meets the Glorious Reclamation at the pass through the place where the Menador and Aspodel Mountains meet.

Gorthoklek's devils can pass through it, and plan A is for them to quickly overwhelm the invaders with more devils than anyone would have dreamed they could bring to the material and retake Dinyar and Isger. But Abrogail isn't actually an idiot and she notices that 'win in the field against unfamiliar weapons' isn't a plan you want to count on, and so the wall of Hellfire is insurance. The devils can travel through it freely; the invaders won't be able to. And it means that she doesn't need the army at the pass, either way; even if Cansellarion's put together an army that can stand up to hundreds of powerful devils summoning thousands of lesser ones, it won't get him onto Chelish soil. They can continue to keep their forces concentrated on the border with Andoran, where they plan to attack as soon as they have determined the capabilities of Good's new guns and the best counters to them.

When the army has approached the hellfire and doesn't appear to be approaching any closer, the devils fly through it. You think you can kill a pit fiend? Fine. Lots of people think they can kill a pit fiend. Try two dozen of them, and immolation devils, and handmaiden devils, and belier devils, all of them surrounded by the lesser devil cohorts they're empowered to summon.

Whatever happens,
We have got
The Maxim Gun,
And they have not.

They don't have that many machine guns, and they haven't yet figured out how to directly enchant them with special qualities, so they are in the hands of powerful paladins with a weapon bond, and in one case a powerful inquisitor with a weapon bond. They are firing silver-electroplated bullets. They are blessed by the good gods. They are enhanced with greater magic weapon.

Cheliax seized a couple of guns in raids in the course of the Glorious Reclamation's quick march across Isger. They're not impossible to make sense of, though they look like they must have taken decades of work to develop and perfect and train people to mass-produce. If they seize a storehouse for the ammunition, they can maybe turn the guns back on their creators at scale; otherwise it'll have to be the occasional shot, to distract or confuse them. They have a sense of what the guns can do; of their range, of how much skill it takes to reload them and fire them. 

They did not seize any of the machine guns. 

They know that the Glorious Reclamation can be very very deadly at range, and that they'll draw fire as soon as they emerge from the hellfire. (They do it anyway, with the summons to distract their enemies and spend down their expensive-looking ammunition and be easily replaced.)

They do not in fact know what guns do at close range until some devils Teleport in to try it. 

...most of the forces of Hell, though decidedly not all of them, escape back into the wall of hellfire within two moments. 

Well. 

Anyone dead deserves it, for being stupid. 

Anyway, it's not as if the Glorious Reclamation can walk through a curtain of Hellfire, even if they can win engagements on their side of it. 

And where's Gorthoklek, in all this?

Not at the front, because that looks lethal and he's in fact not an idiot. He waits in the curtain of Hellfire, trying to evaluate how long it'll take to run them out of ammunition and how well they'll be able to shoot in the dark. 

Would he be amenable to considering these questions on behalf of the other side?

- That is a Dominate Monster. That is a powerful Dominate monster; Gorthoklek has a good many ways to resist mortal magic, and still barely rips free of it. They didn't think Iomedae's forces here had an archmage supporting. He immediately calls out for the appropriate protective spells to be placed -

Protection from Good won't save him. Neither will Protection from Evil, for that matter, but she doesn't want to get into an extended fight with a couple dozen pit fiends in a curtain of hellfire after losing the element of surprise. A curse on him, then, the kind that won't go away without destroying him and can't be easily removed, and a mutual retreat. She'll try again if he ever shows his face again. He probably won't risk it.

- whether to go after Andoran, presuming it to be Morgethai, is Abrogail's decision.

"Yes," she says immediately, "do it. Burn Almas to the ground. Whether or not this is their fault, really."

Lilia is very tired. "If it wasn't Morgethai - I think there's a substantial difference between having her ideologically opposed and having her personally mad and openly involved. And I am not sure it was Morgethai; we don't know her to be any good at enchantments."

"Has to have been her, though, right? They don't have Razmir. Clepati doesn't do …normal things…like try to Dominate her enemies."

"I have no more plausible candidate. And whether or not it was her I'd favor a strike on Almas that could actually kill her, just not one that'll irritate her. ...She may also have sold the Reclamation a scroll of it, at some point, and regard herself as uninvolved.

Also, Clepati may do normal things sometimes, and just successfully conceal them…it does seem unlikely Clepati would try this and fail."

"- there's something we're missing," says Abrogail, who for her many, many, many faults isn't actually an idiot except when she's angry. "We thought the Iomedaens couldn't do this, and they did. We thought they didn't have an archmage, and now one is casting for them. We thought the little bitch on the radio was Andoren, she's theirs. There is a single underlying explanation for the archmage and the guns and the radios. The obvious one is that there is a secret archmage who developed nonmagical weapons and - constructs, probably, that produce them -"