I've been a GM for the entire Carrion Crown now, and this stands out as the thorn in an otherwise good Adventure path.
Book 1 + 2 was very good, book 3 a bit week, book 4 a bit off to a side, but good. Book 5 horrible, and book 6, ok, but a bit too much dungeon crawl. Since it's basically one big dungeon.
*****************SPOILER WARNING**************
So book 5 starts out with the characters having to go to Caliphas, so far so good.
They are confronted with an enemy they have to kill, with a magic item they now have to find a reason behind.
The scenario now presumes that the PC's will investigate this, not too big a leap, with the Order of the Palatine Eye (OotPE), a big assumption but reasonably.
To find out anything, they have to succeed on some very high DC knowledge checks, and not just 1 but 3. DC 27 spellcraft, DC 30 knowledge arcane, dc 40 knowledge history. If any are failed, the story stalls without a bit of fiddling.
My players were actually very brilliant here, they remembered from book 3, that the guy giving credentials to the whispering way was Advion Adrissant, and he was from Caliphas. But there is no mention of him in this book 5, especially not if players actually look him up.
They find the Whispering way HQ to be gone, and gain an ally, claiming they can get info from vampires. This bit is fine. Now they have to go talk to vampires.
But to get there, they have to kill a vampire?! Ok, my players got around that. They talk with the head honcho vampire, who claims to have information, if they help solve the murders. The thing is, he doesn't know anything, or the scenario has no knowledge he has... ok so he is manipulating the PC's? Fine.
They talk to the vampires, which apparently are incredible dense, especially the inquisitor. 30 min. used on talking with all vampires, and they have enough clues to solve the problem.
After a fight with some drug dealers, who hangs out approximately 50 meter from the head honcho....
They find that the documents are false and/or that the stakes are table legs bought by the vampire tailor. And here the chain jumps off again. Instead of going in and killing the vampire, like good little sociopaths, my group just went back to the head honcho and gave him the evidence.
I could have forced them to kill the tailor, but no, their method seemed more logical. So let the vampires duke it out, and gave them his diary.
They get the Nosferatu freed, which only happened because he promised them information, for hey, vampires killing vampires, who cares.
He didn't have any info (Well until the end of the scenario)
After this they have to go to the Abbey, because of some slim chance it has anything to do with the Whispering way.
Kill a bunch of people, and a demon.
But it has nothing to do with the Whispering Way, it just a crazy countess wanting to be younger. Evil perhaps, but in the grand scheme of things, a lot hoo-ha over nothing really.
What really bugs me here? The abbey has a great story, but the PC's have no way to discover the story. Or gain any real insight into why there are spider swarms everywhere.
At the end of the dungeon, they have to fight a bloodknight, and then the boss. The fight is basically in the same room, but is described as two seperate fights. Really bad.
Then they get a letter from the nosferatu telling them where to go... which is basically where they thought they have to go to stop the Whispering Way, e.g. Gallowspire.
So let’s sum up what the PC's did this story? The talked/killed (to) some vampires, perhaps killed a tailor, killed a bunch of people, thing and witches at an abbey.
Hindered exactly 1 whispering way agent, who did not work on the Carrion Crown.
The whole scenario feels like a bad placeholder.
