Valmallos's purpose is to prevent abuse of the laws of magic. Practitioners must be responsible, diligent, studious.

Because it is hard to judge people's character, He achieves this by making magic very expensive and difficult to use, so that only the most cunning and careful and prudent of students grow up to be archwizards without succumbing to the permanent lure of Nethys's explosions.

(Valmallos approves of Nethys. Explosions are an efficient and self-reinforcing method of controlling access to magic.)

The gates and the time stops and the other attendant effects have been flawlessly executed, all the expensive components appropriately destroyed, the raw magic power submitted. Valmallos sees nothing to take issue with.

The planar effect is not magical, and is of no concern to Me, He tells Asmodeus as He leaves.

The city of Dis is heavily fortified. It calls itself Hell's prison, notwithstanding that Hell as a whole is a prison, and it is close enough to the surface to suffer occasional assaults. It is said to be anathema to Dispater to neglect the defenses of one's demesne.

He has not, particularly, attempted to defend against being bypassed. Any army is weak when it is hit in its rear. The attackers must come out of time stop to do anything, and they must retrace their route to escape.

The first Gates to Erebus begin to open.

They fan out from the Iron Scepter. The streets and canals are clogged with demons and damned souls both, making traversing the city in stopped time difficult. The teams mostly fly, occasionally using fixity-teleports to slip into areas otherwise inaccessible.

The streets are paved with souls. The first teams are surprised to see that there are also people tormented into the shape of doors and locks, making every closed door into an obstacle that would stop a less prepared army in their tracks.

Craggy towers of obsidian and metal menace the sky, casting jagged shadows across the winding streets. They comb the city, from the highest peaks to the lowest cellars. They destroy every weapon and scroll, break those parts of the foundations of the city that are not alive. When time resumes and they pull the people out, Dis will be laid to waste.

Lorthact. I speak with Asmodeus's authorization. You are pardoned. Return immediately to Dis. Intercept one of the teams attacking under Time Stop for interrogation. 

It will still take Lorthact until the next round to arrive, but if the attackers persist with the Time Stop, Hell will be ready.

Some of the Dukes of Hell will go into the fight under anti-magic fields. If the enemy relies overmuch on time stops and other magic, it will cost them. Good may field an army of tens of thousands of ninth-level casters, or spend an aeon's worth of hoarded scrolls; they do not have tens of thousands of artifacts. The gates will be closed behind them, and the attacking army will die on the plains of Dis.

The Gates go through to Phlegethon, to Stygia, even unto Malebolge, spreading the invading army across the layers of Hell, spreading it too thin to defend itself.

They will find the planar adjacency to Cocytus - disrupted. The planes themselves will resist their attempts to open more Gates or to keep them open, obeying the will of their Lawful rulers. A few attempts may succeed; most of the spells will be wasted. Those who cross will find opening Gates in the other direction more difficult still.

The steel mousetrap of Hell will snap its jaws, come the moment that the time stops are gone, and all enemies within it will perish.

Erebus is less densely populated than the other layers, not that Weeping Cherry has time to confer with the other teams. She moves through the dark hallways of Hell's treasury, cramped and expansive at turns, vaporizing the hoarded material wealth of Hell.

Space is strange, in Erebus. The only way to venture from one room to the next is through the designated doorway. She makes a map as she goes, showing the corridors and treasure chambers overlapping and passing through each other, making it impossible to be sure how much farther they will have to search to find everyone.

The realm is not purely treasure, however. There are people buried in piles of burning gold, and fearsome martial devils standing guard at each corner. There are people chained to the floor, passing gold and jewels hand-to-hand in the darkness. There are soul-contracts, and ledgers piled high on the desks of devils who bend their backs to the task of tracking Hell's revenues and expenses.

They explore it all, detecting secret doors by the outlines they make in the twisted space, and continuing until they have fully mapped the boundary of the plane and everyone in it.

The invaders fly through the frozen halls of Phlegethon, past souls trapped in the process of melting. They are hammered and shaped by devils as beautiful as they are terrible, their inhuman features an ironic contrast to the dull and oppressive atmosphere of the plane.

This deep in Hell, the air is like a desert. Only instead of water, it is Hope that has been wrung from the shifting winds. Weeping Cherry twitches, and turns to look behind her, unable to shake the feeling that someone is watching.

It's a trumpet archon who starts the song. A wordless, triumphant melody that echos off the grim mountains and pushes back the building fear.

One by one, the other invaders join in, the music mounting into a single brilliant chorus. It resounds off of the towering columns of the forges and over the windswept moors. It reaches deep underground, where doomed souls labor to pull metal and coal from the Earth.

The song speaks of freedom, of the promise that they will all of them escape this place with the next tick of the clock. They break the hammers that Hell uses to beat the hope out of its subjects, and leave the forges ringing with song instead.

Let the forges ring. 

Every so often a paladin comes into Hell, willingly or otherwise, or some party of angels invades Avernus. Hope, hope, hope, they cry down the corridors, marching in, deeper, ever deeper into Hell.

They never march back out. And their cry of Hope does wonders to extinguish it, in those who seem them pass by.

Stygia is a swamp, a putrid miasma of poison and lies swirling around them as they advance. They cannot simply fly over the stagnant waters. There are people under there, eternally drowning in the frigid water.

They dive into the cold and sodden caves, the hidden crevices full of forgotten ruins of civilizations which never stood here. They count each person and overturn every stone. They go carefully, here. It would not do to be misled in the land of the Source of Lies.

Their caution makes the swamps and seas a grueling slog, checking and double checking to be sure nobody is forgotten.

The aura of malice and disgust gets to one of the volunteers, and she bends over to retch.

"Are you okay?" Weeping Cherry asks, patting her on the back. "We can take a break. We're almost done with this section."

  "I'm fine," she replies, and a drop of water rolls from her lips and splashes into the sea, sending ripples out of sight through the trees.

"It will be okay," Weeping Cherry promises. "We'll get everyone out."

The sea doesn't respond. They straighten and continue their work, piercing through Geryon's misdirections to find the truth of the matter.

Malebolge is grey. Endless ash clouds the air, frozen in its gentle fall. It drifts around the bases of the towering trees like snow, only to rise up at the slightest disturbance.

The invaders find people tangled in the roots of the trees, pinned there by sharp tendrils that grow through and around them. They find people in the pits where the cerberi are trained, the three-headed beasts savaging them at their masters' direction. They find people in the fortresses that stand above the silent forests and hold the greatest hosts of Hell.

They find them all, and stand ready to pull them from the ash when this extended moment of stolen time is through.

Malebolge is also the level on which the most of the allied hosts of Heaven are stationed so far, positioned to flank and corral the powerful devils which command Hell's armies if fixity field or Wish fails to move them.

And in scattered clearings across the gloomy forest, the teams destined for Cocytus pound on the planar walls that separate one plane from the next. They hurl Gates at the ineffable interplanar distance, and when those don't work they switch to Wishes, the diamonds running through their fingers like water.

Without a chain of Gates to provide a connection, they won't be able to use fixity fields to transport people out, only to discover them, which makes intruding any further into Hell an expensive and risky endeavor. But expense is no object, and one by one the teams vault the dimensional barrier, and vanish into the antepenultimate layer of Hell.

Heaven is not stupid. They would not waste Wishes without a concrete objective.

Asmodeus can pluck one of them from their time stop, and the mind blank and whatever else they have going. He has power enough, here in His own domain.

He would not be able to understand their squirrely little brains. He can break them, make them tell Him all their plans, but not in time for it to be of use. His Pride still demands it, to not let this challenge to his authority go unanswered, but there is no pride to be had in fruitless action.

He can understand archons, though.

Asmodeus intervenes in His own domain, moving an archon in Malebolge into a time-dilated demiplane, together with two pit fiends and a Dominate Monster ready to go.

The pit fiends move. The archon... doesn't.

...

He resisted a divine intervention, equivalent to a Miracle, on Asmodeus's chosen ground?

It is very hard for Him to make out what is going on under the time stop. His thinking is effectively slowed down by an enormous factor. But hard is, in the end, merely the same as expensive. And Asmodeus has seen enough to pay a very high cost for knowledge. He gathers His attention from across Malebolge, and makes the effort.

This little strumpet archon carries more protective magic than some of His archdevils.

So do all its fellows.

It is not enough, cannot be enough, to withstand the might of Asmodeus Himself, roused to battle.

It takes a second failure, while observing closely, for Him to make it out.

That damnable planar alteration is shredding His magic even as it forms, like some bastardized anti-magic field that excludes the time stop and all the protective magic piled on top.

Is that what it is, then? Localized selective antimagic? But the alteration is spreading in their wake, everywhere they tread, has covered most of the upper planes of Hell even as He watches.

Could it be meant to disrupt magic everywhere it goes? What is going to happen to His Hells, the moment the time stop stops?

Valmallos! What is the meaning of this?!

Still not magic.

Valmallos cannot lie. Or be wrong, in His domain.

It is not magic, but it acts on magic. It is not godstuff (He'd know). That leaves - too many things, really.

Someone invented a new, nonmagical way to interfere with magic. That's their trump card?

They're using a lot of magic themselves. Standard spells, which He recognizes. They ought to have their standard limits, too.

Baalzebul. Channel my Miracle.

The invaders who made it to Cocytus are encased in spheres of flies, overlapping enough to be solid, living barriers to time stops. If they burn more spells to escape these, He can match them, power for power. Acting quickly enough to counter time stops requires all His attention on that plane, but the interventions themselves aren't more expensive for it. (They're still very expensive. This is total war, now.)

Outside the spheres, the plane of Cocytus flexes, as it responds to the will of its Lord and His Overlord, trying to resist the spreading corruption. It won't be enough, but it will slow down its spread, while He searches for answers.

Weeping Cherry startles, and whacks her head on the frozen flies. That is ... bad. Bad, but not unexpected.

Her team had their hands joined, for the transport into Cocytus. They keep in contact, and scan their eyes over the frozen landscape.

"There," an archon says, and they Teleport up to the peak of a towering glacier.

"Something is resisting the field," Weeping Cherry tells them. "I'm pumping some more power in to partially counter it, but since we're disconnected from the main generators we can't necessarily win a shoving match. We have to move fast."

They don't have time to carefully melt the people frozen in the glaciers out and count them, so instead they bounce from peak to peak, using the fixity field to identify and record each soul buried in the ice.

Meanwhile, some of the other teams sit in their initial cages of flies and press on to Caina.

Caina is not like the other planes of Hell.

It is vast, far bigger than a planet, and it is inhabited throughout. A billion spires rise from a vast abyss, millions of miles tall in the everlasting darkness, some sharp and narrow, some wide as mountains. On thin ledges and narrow bridges, tormented souls writhe, and devils are born; but what goes on inside the spires, sealed even from the plane around them, none but the masters of that place may know.

It is utterly dark in Caina; none of its inhabitants make light but one Whose fitful flames are reflected by the passing clouds; but they illuminate nothing that is below.

That is not why Caina is unlike the other planes of Hell.

In Caina, Mephistopheles rules. And He is no mere archdevil.

He is the soul and flesh of Hell given shape. He is the first true devil, and He is a true god as well.

Mephistopheles does not merely rule Caina. In many ways, He is Caina, and His control over Himself is not so easily wrested away, not with the petty mortal tricks of time stop dilation and the artifact trinkets given out by Heaven.

For Mephistopheles to lose control of Caina, it would need to cease being Hell.

The fixity fields go out, six feet out from each generator, and then they stop.

No further. You shall not pass.

Six feet is still enough to save some people, though. The invaders fly along the bridges, cutting support cables and cataloguing who they can.

Six feet is normally a large enough aperture for a powerful telescope, but the flickering clouds of Caina shed no useful light. There is still heat, however. The heat of souls burning in flames of darkness, and the chill of the wind that whistles through the towers, stripping the damned to the bone.

So they let the faint reverberations guide them onwards through the dark, speeding past tortured prisoners and recording them as best they can.

There is another way for Mephistopheles to lose control of Caina, and that is for Him to die.

You were not always here. Hell existed before you. Perhaps it shall exist after you. But from this day, You exist here only on Our sufferance.

And We will suffer Your interference no longer.

The wrath of the gods of Good unleashed descends at last upon Hell.

They cannot defeat Him.

The greater and the lesser gods, in their dozens and then their hundreds, gods never heard of on Golarion, come to do battle as only gods can with one another. But He is the greater; and this is His home ground, which he owns; and has prepared for war, for most of the time Creation has endured.

They never dared attack Hell before. They knew They would lose. Even now, They are burning vast resources merely to keep up, and if They do not soon retreat He shall own Creation by right of conquest.

He still does not know Their plan. And now He cannot spare enough attention from the fight to find out. But there are still allies He can call on in His need.