B1G-SM0NK

I see. Personally I wouldn't do that but I guess it's a different experience.

Well, we also know that it is implied the Grand Queen ordered her son to be poisoned so maybe the brother influenced her to make the choice.

Ah damn.

Do you understand a thing or is it a full on raw experience?

Did you watch it without subs?

Agreed!

The brother and the King care about entirely different things. We see no indication that the brother cares about the corruption and only cares about the downfall of the Kim clan due to what they did to their family. If the brother does steal the ledger and does think that the King is wavering, he wouldn’t give a damn as to what the original plan was as it has already been fudged,

I think the best way to resolve this would be to wait and see the 10th episode and beyond. We can both find points and analysis that will support our beliefs. I still believe that the brother was the one that gave it to Hwa Jin as I don’t think Hwa Jin is a secret ninja.

I also suggest that you spoiler your text.

By E9, he isn’t per se. He is sort of a hindrance to the main romance but I wouldn’t say he is evil.

Grand Queen Dowager and Kim Jwa Geun are siblings; Jwa Geun is the older one.

I agree with your point about the queen and Bong Hwan merging.

Paragraph 1
a) The file is not useless if it lands in Hwa Jin's hands because Hwa Jin can give it to the Queen Dowager who would give it to the representative head minister of the Jo clan. He could easily use it to ruin the Andong Kim clan as it's concrete evidence. He could also use it to make a deal with the Kim clan to maintain the system while also gaining more power.
b) Even the King and brother's plan is not to make the King the most powerful but rather, to uproot the corrupt society that is plaguing Joseon due to the Kim clan.

Paragraph 2
a) There is good reason to kill the queen. There is no way for them to have ascertained whether she heard too much or not. In the real world, anyone planning something like this would not leave any strings loose and would cut them asap.
b) The brother's goal is to uproot corruption and get revenge. I don't see any indication that he cares about the king's power. If he sees that the King is staggering away from his goal, he would not hesitate to betray the King.
c) The brother is part of the Royal Guard who was stationed in the same house. It is not unreasonable for him to hear rumours about their bonding nor is it not unreasonable for him to have seen the bonding from afar and off screen.

I'm sort of debating with another commenter (ponnu) about how Hwa Jin got the ledger so you can find those comments if you're interested.

Hwa Jin usually holds So Yong's book that she scribbles her name over. Yes. However, near the end of the 9th episode, we can see that she is also holding the ledger as the book has the word "Confidential" written.

I skipped through parts of E9 to find my reasoning

i) At 20 minutes, the King says that Kim Jwa Geun does not know that the ledger has switched places. This implies that earlier in the conversation, the King told the brother of the new location hence him saying later on that Jwa Geun doesn't know of the switch. The scene also begins mid conversation so this is a reasonable assumption to make.
ii) At 26 minutes, the brother and Hwa Jin have a conversation. Hwa Jin says that "[the King's] feelings for me have changed". This causes the brother to rush to reassure her using their first official meeting. The scene also cuts by focusing on his concerned face rather than Hwa Jin's possibly reassured face. I would say that this conversation solidifies his belief that the King is wavering as in the previous episodes, the King has refused to kill the Queen and has also started pitying her. Even if we as viewers would think that wanting to kill the Queen is unreasonable, we have to note that from his perspective, it is the necessary thing as she is a loaded cannon ready to blow at any time.

To counter your reasoning:
i) If he tells the brother to go back to the palace without getting the book, it would just raise suspicions that he took the book himself.
ii) If he tells the brother that he has stolen the book, the brother would ask him to give it to him.
iii) As for reasons he might want to do this, go back to the above section. To summarize it's because:
a) He simps for Hwa Jin
b) He doesn't know about Hwa Jin's true nature
c) He thinks the King is wavering to So Yong

Ledger was originally in a hidden safe in the queen’s father’s room (or at least it seemed to be). This is why the King was sneaking around at night and got into a fight with Scarface.

Later in that same night, King searches the safe but doesn’t find the ledger and realizes it’s hidden in the well. That’s why he stays one more day so that he can loot (or try to) the ledger in the night.

I don’t see how else Hwa Jin could’ve gotten it. There’s no indication she’s a ninja lady.

The brother is already on tight terms due to how empathetic the King is to So Yong. I have no doubts he thinks he’s doing the right thing by stealing the ledger and giving it to Hwa Jin.

Iirc they had a secret meeting about KBI investigating the Royal Guards. The King could’ve told his brother the location and how he plans to steal it at night so the brother does it before the King does.

In fact, not knowing about Hwa Jin’s treachery is even bigger reason to give her the ledger as the brother would see her as a “pure” party compared to the King who he sees as faltering for So Yong.

She effectively gets the affection of someone that Kim So Yong shares a bond with?

I would guess because it's still technically the guy's spirit in there and that's gay.

I'm pretty sure that's KBI but it would be strange because KBI doesn't show any indication that he remembers what happens that night.

What the chef gave Choi looks like some tree bark? In my country, we grind a specific type of tree bark as a form of traditional makeup but I doubt that's the use. It also looks similar to cinnamon maybe.

I think that's what the writers were aiming for. Especially since we're supposed to root for the main characters (the queen) and we see that the QD is going against FL by doing shamanistic rituals.

Isn't there BTS on their official YT channel?

I want to watch but don't want to sift through the BTS for other dramas. I wonder if they have a separate playlist for this drama.

I would support the cousin for now. We see that they kissed inside the stable at that fateful night. There may be an extension to that scene where she rebuffs the cousin (since it seems that the scene cuts right after the kiss so we don't know fully what happens after). If the real queen does prefer the King, then I would support the King.