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 -"

It is the obvious conclusion. Lilia hadn't ventured it but it is quite likely what she would believe if she didn't have a different guess. "I think it's a plausible explanation, your Majesty. And would imply this isn't Morgethai, and that we might be well-advised to keep the peace with Andoran, while it lasts, which probably won't be all that long but we'll have had more time to reproduce these weapons by the time it fails."

"And to really put an end to this it's Vigil we have to burn to the ground," says Abrogail, in the voice of a reasonable person.

Which does not make her one. "I do not think we can do that, your Majesty."

"Sure we can! We bribe Arazni! She hates those fucking people as much as I do!"

Cheliax draws down its Worldwound forces to the treaty minimums and has a lot of invisible flying wizards Fireball the forces of the Glorious Reclamation. In the daytime this doesn't go well, because inquisitors can See Invisibility and fire one of the specially-made sniper rifles; at night it's much more of a problem. `

It's not a new tactic, and the Reclamation has all the old responses ready. They camp without night fires, and cover or darken any metal that might catch the moonlight, so the enemy wizards have to come in closer to identify a target; they have their own wizards on night patrol, hoping to catch the attackers in a glitterdust aimed at the fireballs' origins. The only change is that when they succeed it's riflemen trying to shoot the attackers down rather than archers, with predictable improvements to hit rate and lethality. Some of the Chelish manage to both land their fireballs and escape, but even with Cheliax' greater numbers the Reclamation is optimistic about a favorable attrition rate.

Freedom finds military tactics fascinating. For the most part the people who can sit down and explain them to her - the plays, the counterplays, what kinds of advantages are durable and what kinds are altered by guns - are very busy but wherever they are not she'll sit down and talk to them for hours. The non-secret bits she explains on the radio, soberly, including where she's discussing ways that Thrune-loyal forces have an advantage. "We're winning, of course, but there's no point pretending that everything's going our way; no one's going to believe that. If you claim that the war will be won without horrible losses, then when there are horrible losses people might go 'why am I fighting in this war'? So you have to be straightforward. Many people are going to die. We're going to win, though. 

Why do you suppose Cheliax has more people at the Worldwound usually? Because if you have too few, they spend too much time in the field, and they're tired and not combat effective, and they die more. The usual numbers are the numbers that are best for Cheliax in the long run, and now they're eating their seed corn. The forces of Hell have arrived to their aid, and realized they can't meet us in the field because our weapons are too dangerous.

And I'm sure at this point a lot of you are wondering, can't Cheliax steal these weapons? They've tried! But what makes them powerful is that we have ten thousand of them, and the ammunition for them, and by now House Thrune has discovered it can't make them or make ammunition for them. You might think that they can learn how, since people did learn how in the first place, but remember that only slaves, desperate people, and stupid people work for House Thrune, and many of the slaves are now contemplating escape. Invention is the business of free people, defending free countries. Cheliax will be a place of invention once again as soon as it's free."

There's still a wall of hellfire blocking the pass. It must have been an elaborate and expensive miracle, as it does not fade.

There are half a dozen gods who would remove the hellfire as a miracle of their own. The glorious reclamation does not want to try to match Cheliax miracle for miracle, diamond for diamond, even when they can get the miracles from other gods. Cansellarion will look for another way around.

(Catherine could offer such a way, if she was willing to tip her hand to her allies and show a bit more of it to her enemies. She's not at that point, yet. She conjures up seasonal thunderstorms and  unseasonable blizzards to bottle up the Chelish fleets in their harbors.)