There are many things about this section that I really liked. So, as such this (very late) addition to the discussion will likely bear at least some resemblance to a list:
I like that Fallen Invadiah's menace wasn't decreased even though her power was, through her demotion from Erinyes to Succubus.
Two things struck me here in Chapter 17 and again in Chapter 19:
1) Mira's independence as a strong female character (YAY)
2) I also like the hints that Mira’s true Master/Mistress is the Past. Her historical/archaeological leanings make themselves clear on occasion, such as having to bit her tongue when Pernika took a pry bar to the door, and prove themselves to be her primary concern when questioned by Tam. She seems to be willing to work with anyone if it lets her do the things she is passionate about doing.
I have to say that I very much liked the image of the ghosts just grabbing the nearest handhold on a person and leaping off the pit edge. No worries about pushing at that point, just the dragging. Not choosy about what they grabbed either. Pernika by the hair and Tam by the leg! Though given their obvious enjoyment it does make me wonder why, at the end of chapter 17, the rest of the ghosts went after Tam and Pernika, into the depths, rather than trying to get the rest of the party into the pit with Tarchamus.
The reveal of Tarchamus in Chapter 18 was nicely done. It followed, what I imagine would be, the way that details would sink into the perceptions; pose, texture, details, face. It was very eerie and quite, quite horrible, almost as horrible as the mental image of Pernika's fate.
During the battle itself there were some clear high points, for me, in the narrative. The combat-healing by Dahl, the setting of Tam's leg was good. This one act set the seal, for me, on any misapprehension of this lot coming out like Hollywood Heroes... with perfect hair and only mildly singed clothes and a smudge of dirt on one cheek. The fact that Brin, even after attempting to apply Divine magic, wasn't sure he'd managed it was a nice one too. Hubris wouldn't be a good look for him I think. The battle had a good degree of verisimilitude. An example of this, and something I really liked, was the idea of the Brimstone stink and fumes from Farideh's teleports *collecting* in the bottom of the pit. Something that really spoke to me of attention to detail and Erin having thought out the effects of Fari’s actions!
The location of the mid-battle cut was either superb... or very mean. Cutting back to Lorcan when everyone was out of the pit except a battered Fari, Dahl and an enraged Arcanist really ratcheted up the tension (from high to twanging point). I almost inhaled the section between Lorcan and Sairché because I needed to get back to The Party. Having said that, I always enjoy the interplay between Sairché and Lorcan, and so even at speed I lapped it up. I have also become so untrusting of the devils that Erin portrays that I half expected Fallen Invadiah's pearl to be a trick, something to make Lorcan give something away before thinking he was about to escape... and then not doing so.
The battle.... oh the battle. My word what a mess. Not the writing, that was superlative, but with people going up the pit, down the pit, Farideh teleporting, Lorcan plane-jumping, Dahl deciding he feared his own death less than what he would have to explain to Tam... and Lorcan's sisters turning up... What an unholy mess!
One exchange in the battle that stood out, with the sense of wry whimsy that I so enjoy when it turns up in Realms writing, was Lorcan's "Is your paladin out of the way?" "Yes." "Pity,"
The fact that the air shafts were in The Pit seemed a bit convenient to me, until I reasoned the thing out. If Tarchamus and his servants based their existence on consuming those brought into the Library. Then the rest of it makes sense. Sealing the doors forces the prey to seek other exits, which brings them to The Pit. The only way out is through The Pit. So as long as Tarchamus (Mr. T) and his ghosts believe themselves invulnerable, then placing their lair directly across the only way out makes perfect sense. The prey will always come towards them!
The aftermath was well played out, if a little odd for the sudden stillness inherent in the scene. The battle has ended, a five minute rest and yet they have not been menaced during this time.
One thing I did like about the “enemy of my enemy” moment was that it didn’t feel forced. I do wonder, though, did you have this moment in mind in the beginning Erin? Or did the narrative just organically evolve towards it as a result of the factors that you put in play? Even Farideh’s diatribe at Tam didn’t feel incongruous, as it so easily could have.
The revelation about the blood magic? Pretty much expected at this point. As was the destruction of the wand. The fact that Fari would extend the protection? And the object lesson of how close they would need to stay? Now that was a surprise. An amusing one though.
I will post more when I finally finish the book!