The journey to the Forge of Vengeance took Aoko's party about two and a half days. The straight-line distance wasn't that long, but the Underdark's terrain was so convoluted that they couldn't use mounts or fly above ground.
Actually, it's not that flying is impossible, but it's less efficient than walking, with monsters lurking in midair and stalagmites blocking the way—one careless move and you'd crash.
Naturally, you can't travel the Underdark without danger. On the second day, Aoko's party was ambushed by a pack of phase spiders led by a queen. These monsters were numerous, tough, and could teleport at will.
Fortunately, that morning Aoko had used divination to predict she'd need Dimensional Anchor, and prepared in advance.
By anchoring the phase spiders, she prevented them from teleporting away and counterattacking after her teammates struck.
Even so, there were a lot of spiders—Aoko had to cast Chain Lightning twice, leaving the air thick with ozone and the smell of burnt protein.
The phase spider queen was split in two from head to toe by Xenk's Holy Smite, ending the sudden skirmish.
Normally, encountering monsters in the Underdark is bad news—but phase spiders are an exception.
Their silk is a rare material, used for expensive enchanted scrolls (as a base) and certain special robes, fetching high prices on the market.
Since phase spiders are so rare in Faerûn, their silk is usually bought internally by organizations, and lone buyers pay dearly.
Aoko collected the silk happily, planning to have Habetrot make her some special gear.
"We're here," Xenk said, standing behind a sharp black rock, gazing at the brightly lit city ahead. "This is the duergar's pride: the Forge of Vengeance..."
"The Forge wasn't actually designed or built by duergar," Aoko explained, taking out a spyglass and observing the city. "Like Gracklstugh, it's a gnome creation—the duergar just conquered and occupied it."
"Look," Aoko pointed. "Even now, there are lots of gnome slaves inside. The duergar can't handle the adamantine forges—they don't have the skill."
"Is there any way we can help those poor gnomes?" Xenk asked, frowning. "They shouldn't be enslaved!"
"But there are too many duergar," Edgin whispered. "There's only six of us, and there might be drow in the depths!"
"...It's not impossible," Aoko thought aloud. "Did you notice the things the gnomes are wearing?"
"Aren't those just handcuffs and foot shackles...wait, some are different! Those are anti-magic!" Simon exclaimed.
"Exactly," Aoko nodded. "If they're wearing anti-magic devices, that means some of the gnome craftsmen are spellcasters. If we want to overthrow the duergar here, freeing and using the gnomes' power is our best bet."
"...You've convinced me," Edgin said, after pacing for a moment. "Fine, I'm in."
"Anyone disagree?" Aoko asked, looking around. Everyone nodded in agreement. "Good. Let's start with recon!"
Reconnaissance was the first step. Aoko didn't use Arcane Eye, but instead gave her familiar Stark a stealth anklet and watched through his eyes.
Since the Forge was huge, Doric transformed into a bat—a common shape in the Underdark—to scout from another direction.
Aoko watched Stark's progress and mapped the Forge and enemy positions in her notebook. After about forty minutes, Stark and Doric returned.
"I've mapped a route to the gnome slave camp," Aoko said, pointing at her notebook. "The duergar are trying to repair some old structures, so they've concentrated most of the gnome workers here."
She pointed to the northwest part of the map, tracing a route there.
"There's only one entrance and exit, guarded by four duergar overseers," Aoko continued, "but one wall has no guards and a barred window high up. We can use Simon's teleportation wand to get in and silently take out the overseers."
"Doric, what did you find?" Edgin asked.
"Here," Doric pointed to the central part of Aoko's map. "This room is badly damaged, so there's a group of gnome slaves digging."
"But it's an open area," Xenk observed. "If we fight there, we might attract a lot of duergar reinforcements."
"Not only that," Doric shook her head, borrowing a pen to mark a red X. "Here, there's a drow spellcaster—could be a wizard or cleric—with a squad of heavily armored duergar."
"Why is he there?" Aoko wondered. She was sure this wasn't the timeline from Baldur's Gate 3, and this drow wasn't the unlucky one buried alive. "Maybe he's some kind of project manager?"
"I don't know," Doric shrugged. "He seems to be supervising the dig. There's a blocked archway in the open room—maybe there's something they want behind it."
"...No point overthinking it now," Edgin said. "Let's follow Aoko's plan: free the gnome slaves in the northwest, talk with them, and then figure out the rest. The more people, the stronger we are. Sound good?"