This story takes place the day after the previous episode, wherein the Glass Breakers – now joined by a forest gnome wizard named Bayesian Chance, whom they met after a sudden encounter with a group of orcs and a manticore – continue their venture through Wave Echo Cave. By this point, the party had a few close encounters with a couple of undead, found and opened the Forge of Spells, and took down a number of the Black Spider's remaining forces before coming face to face with Nezznar himself. Or at least, that's what they had initially thought before learning that the drow they were seeing was simply an illusion.
Not long after opening the Forge of Spells and electing to take a rest there, the Glass Breakers were met by a few more goblinoids of the Cragmaw Tribe, as well as the same illusory form of Nezznar. After a fairly fierce battle, after which Rare, Bayesian, and Ghesh were left severely wounded by a last-ditch fireball the hobgoblin devastator had let out in the midst of its impending doom, Nezznar was finally revealed to not actually have been a drow like they had initially assumed, but actually a drider. Thus, having found their target and more than ready to take him down, the fight was on!
They quickly found Nezznar to be fairly tough, managing to take on a fair number of their attacks with a fair amount of ease and simply block some of the strikes the only barely managed to slip through his defense with a quick Shield spell. The fight gradually grew dire as they then found themselves being approached by more goblinoids in one corner and a pair of giant spiders, one of which had managed to latch onto Ghesh, a few seconds after the first group's arrival.
Thankfully for themselves, the Glass Breakers were also putting as much of a fierce fight in response to the rapidly-escalating tension of the battle, with the frontliners managing to get a few good blows with their weapons in, even with Nezznar casting Shield on reaction to momentarily strengthen his AC, and Bayesian managing to sneak some damage in through Toll the Dead, which required a Wisdom saving throw that I just so happen to have bad-enough luck to roll low on; granted, Bayesian's high Intelligence stat, and high spell save DC by proxy, certainly helped.
However, two rounds after the fight had begun, the fight seemed to begin tipping in the Black Spider's favor once more, as another group of goblinoids showed themselves. However, this time, they were accompanied by none other than Iarno Albrek, whom they had earlier subdued in Phandalin several sessions ago after learning of him being the one behind the formation of the Redbrands and their subsequent takeover of the town, and the battered and weakened form of Nundro Rockseeker, the other of Gundren's two brothers, currently in the wizard's clutches.
Confident that his victory over the Glass Breakers was at hand, Nezznar took a moment to arrogantly gloat once more, as he provided them the potentially sadistic choice of doing as he would tell them in exchange for Nundro's life or risk death. Naturally, being the stubborn adventurers they are, they refused to back down.
"Bah! Very well then," Nezznar responded, arrogant as ever. "Do your worst, fools!"
"Gladly!" suddenly cried the voice of, to the surprise of everyone, Iarno as he promptly let go of the dwarf and pulled out a spell scroll he had obtained some time earlier. The scroll quickly revealed itself to contain the spell, Hold Monster – which would work perfectly against a non-humanoid creature like a drider. After barely succeeding his Intelligence check to use the spell scroll, Nezznar was then forced to make his Wisdom saving throw against the spell. I don't exactly remember what I ended up rolling, but I'm sure it wasn't enough to beat the spell scroll's save DC of 17. Thus, Nezznar found himself paralyzed and unable to do anything.
Nezznar attempted to speak, though his paralyzed condition prevented him from doing so. Seeing that his gambit seemed to have worked for the time being, Iarno then turned to the party and firmly spoke, "Finish him."
Without wasting a second's breath, Riku immediately got to work and slashed the paralyzed drider as hard as he could. In his paralyzed condition, each hit he managed to land on Nezznar was an auto-crit, leading to massive damage on his part. With all of his might, Riku swiftly cut the Black Spider apart with his blade, putting a swift end to the mastermind behind the Glass Breakers' recent troubles.
The goblinoids that were still working alongside the Black Spider were then intimidated into leaving by Jameson, with the hobgoblin captain among them leaving behind a pair of gauntlets, partially out of respect for the gnome's bestial strength. However, the fight wasn't quite over yet, as one of the giant spiders had managed to knock Rare unconscious and leave her poisoned, and the dwarf – actually Vyerith, who had assumed Nundro's appearance before promptly shifting back to her drow form – then charged at Iarno in a successful attempt to grapple him.
With Vyerith having finally shown herself, Nigel then took the opportunity to finish her off as he had intended ever since their last encounter. It turned out that the goblinoids that had shown up with Iarno appeared to be on the wizard's side, as they then proceeded to make their own attempts to hamper her down while Iarno successfully slipped past her grasp with a Misty Step spell.
With the assistance of the two hobgoblins, Jameson, and even Iarno via a Hold Person spell he had cast on his next turn, Nigel finally got to viscerally rip Vyerith a new one as she was subject into a gruesome series of blows from the hobgoblins longswords, Jameson's rapier, and Nigel's goedendag, ending with Nigel pinning the doppelganger down onto the ground with as much brute force as he could.
With the last of the Black Spider's compatriots finally dealt with, the threat he would have posed had he succeeded in his plot – whatever it may have been – was effectively thwarted.
After the remaining goblinoids of the Cragmaw Tribe had taken their leave in currently non-hostile terms, the Glass Breakers are then guided by the seemingly-reformed Iarno to where Nundro was being held and soon made their way out of Wave Echo Cave and back to Phandalin, their mission finally accomplished.
On the way, Nigel pulls Iarno back and begins to question him about all of his recent actions in the last few weeks – the Redbrands, his working with the Black Spider, and why he had suddenly turned against him at the last possible moment.
With a deep breath, Iarno explained, "When I was first assigned to help establish a proper authority in Phandalin, I would be lying if I didn't admit to being excited at the prospect of possibly gaining the recognition amongst my peers I so desired. In that pursuit, my excitement then quickly turned into a gravely-misguided sense of ambition and lust for power, leading to the formation of the Redbrands and my forming ties with Nezznar."
"Not too long after Sildar and his new friends had forced my surrender after my desperate last effort had ultimately failed, I eventually found time to reflect on everything I had done thus far," Iarno continued. "I was then able to realize that I truly had lost my way – far quicker than I would have thought. The Black Spider may have been a fool for his ultimately-futile pursuits… but he was nowhere as foolish I was. With that said, turning on Nezznar and assisting you in the process is not nearly enough to make up for it, and so I fully intend to face judgment for my misdeeds."
With a frown, Nigel then rebutted, "Look, Iarno, I can see what you're gettin' at, but if you really wanna atone for the shit you pulled, then your energy will be better spent actually going out into the world and helping people rather than just rotting in a jail cell."
I then had Nigel roll a persuasion check to see how Iarno would take this, though he unfortunately ended up rolling a total of 3. Iarno, appearing not wholly convinced of whether that possibility would even be open to him, firmly replied, "…I'll keep it in mind."
With that conversation put aside for the time being, Nigel and Iarno then continued their way along the path back to town as they caught up with the rest of the Glass Breakers.