Last Factory
Frost 1, 833 I. E.
16 Years after Albert's Exile
Keep of Rentar-Ihrno, Secret Caves of Upper Avernum
Albert, Sschass, Helen, and Frruh entered the doors of the great hall, weapons ready. The other vahnati had been defeated, the magical machinery primed for destruction. But the final controls they needed to activate were in this room. They had to finish the mission, and prepare for their own destruction.
Rentar-Ihrno was waiting for them in the center of the enormous hall. Albert didn't often get to see Frruh when he was about to fling powerful magic, since Albert was usually at the lead with Sschass, but he'd seen Frruh's hands glow with contained power during practice. Rentar-Ihrno's hands were glowing a different shade as she prepared magic that was already raising Albert's hackles.
Rentar-Ihrno called out, "If you had closed your eyes, Avernites, you would've been the empire ruling all the surface. How much you destroyed for the sake of wicked men who exiled you!"
Albert's gut twisted - not from doubt, but from horror. Avernum would've become the Empire if they hadn't made this stand.
Helen called back, "How many would've lived if you hadn't manufactured murder?"
How he loved her! But how would they make her words bear fruit? Albert had no better plan than their original.
So, together, the Avernites charged Rentar-Ihrno - but soon stopped in shock as the medallion Erika had given them began to glow, and the archmage herself teleported ahead of them, a short distance from Rentar-Ihrno.
Erika fixed a grim smile on Rentar-Ihrno. Then the incantatrixes began to throw at each other some of the most potent magic ever seen. The flashes and blasts of heat, ice, lightning, and acid, sprayed over the hall. Frruh hoped that Erika, at least, was trying to shield them, or at least not get them caught in the worst blasts. Between the ferocity of the mages' duel, and the hordes of powerful creatures both combatants summoned in short order, the massive hall was soon filled with perils of one sort or another.
"This way!" Albert shouted, waving his hand in a chopping motion. They started running forward, but found a pack of cave widow spiders were cutting across their path. Thankfully, they were among Erika's summons, and were concentrating on an eyebeast Rentar-Ihrno had called out of a soul crystal. Still, a course change was necessary, and there were few places to go.
"This way!" Albert called again, pointing in a different direction.
Helen looked with concern at a rearing, twenty-foot worm, covered in six-inch spikes, that would be bearing down on them if they chose that path. "Are you sure that spinebeast is one of Erika's?" she called as they started running.
"No! Wish they wore uniforms!" Albert shouted.
Frruh threw a fireball ahead to clear their path, and did manage to obliterate some of the ursagi ahead of them which Rentar-Ihrno had summoned. Albert parried one blow of a naga, but the Radiant Shield from Helen and Pachtar's Plate Mail had to take the brunt of the second. Albert and Sschass finished the naga off together, and Helen cast Divine Retribution, slaying chitrachs following them. Albert charged at the next summons between them and the control pedestal, but Sschass shouted, "We can't afford to stop!"
Albert looked back and saw that they were just beyond Erika and Rentar-Ihrno, both enclosed in powerful magical shields and throwing every spell in the book at each other. Their summons were now a mighty throng filling nearly the whole hall, their melee spilling between the adventurers and the control panel. The menagerie milled, writhed, and charged, a stormy sea of flesh, fangs, ice, hair, scales, fire, and tattered bones, all howling and frothing together. The sheer magical energy being thrown by the incantatrixes at each other was making hair stand on end, and the monsters were among the mightiest the band had ever seen. Whenever one fell, the mages summoned more to replace them. The adventurers would never make it through the last half of the hall if they fought the summons, or even defended themselves.
The adventurers quaffed hasting potions, Helen shielded them as best she could, and they ran for the lives of every surface dweller, and every Avernite who hoped to ever live there. Punishing blows rained down on their armor, and they abruptly changed direction to avoid friend and foe alike, as a hundred melees erupted and concluded around them. They dove under the claws of drakes, hurriedly edged past the tails of wolves as big as them, and friendly only because Erika had happened to summon them, then veered away from a barbaric contest between ogres and rakshasa - who fought for whom in that gorefest was totally unclear.
But at last, they gained the console -and Albert boggled at it. "I can't believe it, it's not going to work," his lips said of almost their own accord.
"What does it say?" Sschass asked concernedly, as he tossed a javelin at an ur-basilisk whose stare was clearly unfriendly.
"It's controls for the factory's magical goo, all right, but I don't have time to figure out how to destroy the system from here. I'll just have to smash the console," Albert said urgently.
"Wait, I almost have it!" Frruh shouted from over Albert's shoulder.
"I'll give you as long as I can!" Albert told him in passing, hurrying in front of the console to help Sschass fend off a wight.
Helen cast another bolt of ice, though she nearly collapsed and began to retch. When she regained control, she hurriedly unstoppered a restorative potion and quaffed it, and with her renewed energy had to immediately heal the whole party.
Frruh punched some buttons, and they thought they heard a rumble above the chaos of combat.
Rentar-Ihrno flung a powerful but small and concentrated bolt at the ceiling of the keep. It burned through the ceiling, then after a moment, there was a low growl of stone melting, and then a single shaft of light from the surface fell on Erika.
A pile of ashes crumpled to the floor where she had been standing. All but Frruh, who hadn't seen, covered their eyes - both the light and the Empire's fiery curse devouring Erika's body had stabbed into them. Frruh looked up to see Rentar-Ihrno turn her gaze on them.
Then there was a rumble and a series of explosions from far off. Rentar-Ihrno shouted something in vahnati that was clearly angry. A moment later, she had teleported away.
Sschass cursed in slithzerikai, but it was no small thing to have foiled her plans.
Helen turned to Frruh. "Brilliant!"
Frruh said sadly, "It was good knowing you all."
"At least we'll be with friends," Sschass said, and though no one was sure who reached first, they all joined hands in a circle.
"So now we just need to trust the Empire, huh?" Albert joked as the ground shook with nearing explosions.
A moment later, they were teleported into the Empress' throne room in Blackcrag Fortress.
Frruh took a slight step back from the surprise, and the vertiginous effects of teleportation. The empress' mage who had just teleported them still had hanging in midair a scrying of what was going on in the great hall of Rentar-Ihrno's Keep - a large explosion, then patches of fire and collapsing masonry.
Sschass and his friends breathed heavily as they looked up at the dais where the empress sat. She stared down at them a moment before saying, "Well done, Albert, Helen, Sschass, and Frruh. The deal is fulfilled. The land described in the treaty is now Avernum's."
Albert looked between the mage and the empress and said through labored breathing, "Thank you."
Empress Prazac replied, "On behalf of every living thing on the surface, thank you."
Author's Note: The dialogue I basically made up, because I don't recall much, and similarly for the specifics of the fight (did Erika and Rentar-Ihrno encase themselves in powerful magical shields?) but the basics of Erika's death are right.
I hope I am remembering that Radiant Shield could be cast on anyone, but it may only work on the caster.
It may be an exaggeration that you couldn't possibly get through all the summons if you stopped to fight them - but there were an awful lot, and they were tough, and they weren't your objective anyway.