What would the leadership of Kintargo know if they PCs captured them and interrogated them? After all, the Lucky Bones has some natural defenses against divination (flowing water vs. locate person), jail cells, and is unknown to the Thrune occupiers. If the PCs want to, the NPCs can be captured and interrogated.
What would these people know about Thrune's plans?
- Zella Zidlii
- Corinthian Grivenner
- Kyrre Ekodyre
- The Gardner
- Tiarise Izoni
- Vannases Trex
Would they know about the plan to become a genius loci? Would they know where the soul anchor is?
Would they know the fate of Jillia Bainilus? of Shensen? of Jackdaw?
What city secrets would they know?
What would they know about each other?
If captured before book 4, would they know about the Masquerade Ball false flag operation?
According to book 6, "Rivozair along with characters such as Corinstian, Tiarise, and Aluceda" accompanied Barzillai to the Soul Anchor and would therefore know where it is and likely have an idea about his Genius Loci plans (Page 37).
I imagine Zella wasn't seen as required for the ritual but she may know where it is as Barzillai likely tried using her Divinations to try to locate the Soul Anchor (which would have failed to locate it but she may have help him discover it through other means). Personally, I'd go with her not knowing anything about it. Barzillai plays things fairly close to his chest and wouldn't want unnecessary people knowing about his plans.
Neither Kyrre, Vannases, nor the Gardener likely know about the Genius Loci plans as they're 'protection' and don't need to know. ("Need to know" basis.)
Aluceda obviously knows about Jilia therefore it would make sense for Corinstian to know. Rivozair would know. I don't think anyone else would have a reason to know.
Knowing about Shensen would fully depend on what you want the NPCs to know. Kyrre is the most likely one to know, the others... not so much. (And even with that, I don't think Kyrre would know). Shensen went to confront him on the Night of Ashes, it became a fight, he cast his spell and moved her to the basement.
Barzillai and his crew don't think Jackdaw is important (due to redacting and the record in D7 of book 4 only list her by name with no context and apparently no one working for Thrune recognizes the name of someone that was a folk hero only 80 years ago...). Kyrre likely knows the name but wouldn't think anything of it/relate it to someone that the PCs might consider important.
That being said, Thrune was mocking both Shensen and Jilia about Jackdaw being down there so book 4 also shows that Thrune DOES know who she is...
To avoid all of that, I knew that my group would go through the whole place even if they didn't know she was down there. I had the lyrics for the Song of Silver under the opera house and had Jackdaw humming the tune. The bard in the group easily noticed that the words went along with the tune so figured out who she was (her crypt being empty below the opera house made it fairly obvious).
Oh, and I had the lyrics be the thing under the opera house because it's weird to have the sheet music without the lyrics written above the notes. But having lyrics without the sheet music is common enough to not look weird.)
As for other city secrets/secrets about each other... depends on the relationships you want them to have. They probably all know/assume Aluceda is a vampire, none of them likely know about Tiarise's "Binding the Soul to the Stone" ritual. I had Tiarise and Zella work together for a lot of different missions so they'd know more about each other in my game, but your game is likely different.
Knowing about the Masquerade would depend on how much before the end of book 3 that they were captured. The Masquerade is a result of knowing that the PCs are opposing his rule and they're becoming much too popular for his liking. Since Dottari and used to prevent the escape of Kintargan citizens that would mean that Vannases would have to know about the plan. It would make sense for Kyrre to know about it. The others probably don't know about it as they're not involved. (I would think that Kyrre knows about the plan first as it's her hellknight order that's in charge of putting down the rebellion. Vannasses might not know about the plan until shortly before the ball.)
For the Masquerade, it would also make sense for Rivozair and Corinstian to know as well as the former needed to relocate and the latter provided Cizmekris for the deception.
I also like how no one is bothering to figure out if Tombus knows anything, since Thrune just views him with contempt and probably doesn't tell him anything anyway.
Funny enough when I ran this Tombus is the one the players managed to capture.
I think by the end of the first interrogation the party came to the conclusion that he was so pathetic and foolish that there was no way he actually knew anything valuable and proceeded to forget him in the hideout's dungeons.