How can I do this quest? Guides say that Stale Mary will take you to him if your charisma is above 16, but all she does is say "suhhhhlent kiiiiingggg" repeatedly.

The only way I can find to do this is to filch a key from Hagrim, then unlock the door to the throne room, and see the silent king in person. But doing this turns the entire Dead Nation hostile once I open the door, and I don't want that.

You probably have to be able to speak correctly to Stale Mary. If you talk to Haggrim about her he'll tell you that you have to "listen" to her. So, go talk to her, listen and try to get her to take you to the Silent King.

I think that should work, I actually am playing PS:T for the first time and just got past that part myself, so I'm not an expert by any means.

I already got the ability to "listen." Stale Mary will talk about other denizens in greater... detail.

I can't talk to Hagrim about anything except resting and healing.

I'm under the impression that Mary won't take you to the SIlent King if you already done Hagrim's quests and you're no longer a prisioner in the Dead Nations, but i'm also no PST expert .

I just did it by killing Hagrim and nicking the key which gives you access to the Silent King. He is quite hard to kill though, but being immortal its just a case of going back and forth until you kill him!

If I recall correctly you may only see the Silent King if you have not yet escaped by some other means. I hear Thieves can pull off a spectacular stunt in the throne room - if you are one you probably want to go back to an earlier save. (Bring a human skull).

I believe you either have to continue dialogue w/Hargrim, or you get a quest from Acaste and then tell what Acaste told you, to Hargrim.

I didn't do either when I was there, though. I roleplay that TNO, Morte and Dakkon decided that the power balance between the zombies/skeletons vs. ghouls vs. the Warrens of Thought vs. surface dwellers was way too delicate, that I thought it best to leave it all alone, after doing what we could help the local concerns and doing the task that Pharod sent us on. Acaste is simply too ravenous to deal with in any manner or fashion.

That, and the fact that you're deemed a slave of theirs upon entry in their domain and their king doesn't care one way or two about it, made me think that you weren't really welcome in his presence in the 1st place!

SPOILER below!!!!! Don't read if you intend to persue the Silent King or haven't fully explored the Dead Nations!!!!!!!!!!!!!!!!!

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I believe I read on a PS:T website some time ago, that the Silent King decided to die by Soego's doctrine, and thus you can't meet him. But Hargrim goes on as if he's still sentient and animated, so to not upset the balance of power, as if the undead citizens knew that the Silent King was no more, that then Acaste and her ghouls would feast upon the zombies and skeletons. I believe that is the result the OP would find upon persuing this quest.
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