Thanks for clarifying, its been years since we played (it was a few months following its release) the campaign. Personally I found chapter 8 to be the weakest it was essentially a travelling to Kislev chapter and was pretty boring and would have required immense amounts of additional material from me before I would actually play it but as things happened we didn't get that far, my party got fed up and half of them saw though Karl's mutation from the start, I cannot remember how or why it happened but they Killed Karl, the real one and chased down the fake ones as well just to make sure way before we got there which was a relief as I wasn't looking forwards to that big dungeon either, Dungeons have never worked in Wfrp beyond the scope of a large house because combat's so deadly the players should have the chance of being able to avoid it realistically most of the time, that dungeon was not one where that would have been possible so it would have gotten dull quickly. Even the fantastic Dungeon in Lure of the Liche Lord had myself (DM) and my players somewhat fed up with combat by the end of it, so much so I let them avoid the final confrontation with the Liche allowing them to negotiate favours with him, now that Dungeon was wonderful though being as it was loaded with information, traps and overall pretty light on combat but hell was it deadly.
Anyway back on topic my personal favourite chapter was number 7 but I felt that the writer was trying to relay far too much information in far too small a amount of space and I also feel the expansion material for this later released by Libra Fantatica goes a long way to staggering this information as well as solidifying it in one place for the DM. Honestly though overall I prefer Warhammer fantasy at early 3rd career of development at the top end because I find it becomes silly at higher levels of play and that the RPG engines (Mechanically 2nd or 3rd, not knowledgeable enough about 1st to make an informed opinion) are simply not designed to handle Characters of that ability level. Also while I love the 3rd edition dice system, I feel that it should have been brought in for Starwars instead and instead a improved version of the 2nd edition system should have been used instead for WFRP, this is for multiple reasons; The amount of content already in existence that could be used would have allowed the writers to explore new areas of the World rather than going back over previously covered ground (in less detail as it turned out); Secondly while the 2nd edition rules were far from perfect, the big issues could have been fixed within that system using a lot of the same mechanics found in Dark Heresy (1st & 2nd edition) allowing again for a far more polished rule system rather than a new system with its own massive flaws, especially when the cost of that system is entered into the equation (its the most expensive RPG I've ever owned).
Anyway off topic rants aside (because I'm pissed with how WFRP has been treated by FFG, though not even close to how strongly I feel about what's just happened to Warhammer) I'm not surprised Nathan Long wrote that chapter because you can see Ulrika and her sire in those Lahamin's clearly, I've always thought that's who they were based on, but not actually used because of it causing issues with there and his narrative.
Yeah, the vampire thief running on the roofs of Altdorf was clearly a nod towards Ulrika. I liked that a lot actually.
I really liked the storyline of Nagash in TT. They've gave him interesting background, the mystery of the tilean box and its creator was very cool and challenging and the ending where he returns and posseses Karl's body was much more interesting than the one with the Black Witch and her spider army.
I disagree however about the 2nd's mechanics. While not perfect they still work good enough, albeit high level PC's tend to derail the game a lot. I can tell that from my experience as both a long time GM and a player, for whom WFRP is a game of choise. Dark Heresy would certainly not help WFRP, as WFRP's mechanics are Dark Heresy's biggest problem, being mechanics meant for a close combat setting and not one, where you shoot bolt guns at one another. DH is a system that needs a lot of tweaking if you want it to work at all. WFRP you can tweak, but it's not necessary IMO.