The Fires of December speculation

[WestwardWind]

Alright. We received the first chapter today, and immediately I began to wonder “What planet does this take place on?”

Here are my theories. 

1, it’s Ashyn. I know this isn’t very strong, but certain things seem to interlock in ways I can’t ignore. The fire in the sky, the war, and the king betrayed. This sounds similar to the story we hear in Stormlight about Ashyn. The plague is also suspect, because what we have of Above the Silence Prime, it sounds similar.

2. It’s Yolen. Mostly based on the fact that the king was murdered by one of his dukes. This is very similar to the tale of Jerick told to us by Hoid in Stormlight 5

3. Mythos. The tale sounds very mythology in nature. That’s it.

Or it could be on another, unknown planet. I’m just spitballing here before we get more information 

[Through the Living Shadow he/him]

19 minutes ago, WestwardWind said:

Alright. We received the first chapter today, and immediately I began to wonder “What planet does this take place on?”

Here are my theories. 

1, it’s Ashyn. I know this isn’t very strong, but certain things seem to interlock in ways I can’t ignore. The fire in the sky, the war, and the king betrayed. This sounds similar to the story we hear in Stormlight about Ashyn. The plague is also suspect, because what we have of Above the Silence Prime, it sounds similar.

2. It’s Yolen. Mostly based on the fact that the king was murdered by one of his dukes. This is very similar to the tale of Jerick told to us by Hoid in Stormlight 5

3. Mythos. The tale sounds very mythology in nature. That’s it.

Or it could be on another, unknown planet. I’m just spitballing here before we get more information 

Hey! There's already a speculation thread, lemme pull it up.

 

I did think Yolen, but rn what I'm thinking up is

Stormlight 5 Spoilers

Spoiler

it's Valor's own version of what Taravangian did with Kharbranth by sending it to the Spiritual Realm, and

 

non-spoilery: it takes place

in the spiritual realm

other people have other theories! you should check it out

heres the link (once I get it)

 

Edited December 13, 2025 by Ookla the Ansible

[We_need_more_sel]

I think FoD will take place on either; Ashyn

On 12/12/2025 at 7:41 PM, WestwardWind said:

 it’s Ashyn. I know this isn’t very strong, but certain things seem to interlock in ways I can’t ignore. The fire in the sky, the war, and the king betrayed. This sounds similar to the story we hear in Stormlight about Ashyn. The plague is also suspect, because what we have of Above the Silence Prime, it sounds similar. 

Ashyn was described as a disease Investiture planet by Sanderson. Opening chapters have two major diseases December's and the plague.

Or Sel because the demon river Investiture is part of the land or something. Also the Dor is the only source of Investiture we know of with enough power to use Fourtune visions on accident I think.

Or ancient Dhatri because the river seems like aethers. It is described as dark and oil like so maybe the "prophet" contained the demon keeping it from gifting the aethers to create aetherbound because they saw Midnight Essence as too dangerous in the future. The sword could also prevent anyone else from using that demon's aether.

Random thought is yumi and the nightmare painter maybe set on a plant created by Whimsy? The ridiculousness of stacking stones for Investiture and spirits liking TV romances or whatever it was seems like a Whimsy planet.

Edited April 18 by We_need_more_sel

[Atlas333]

On 4/18/2026 at 1:32 PM, We_need_more_sel said:

Random thought is yumi and the nightmare painter maybe set on a plant created by Whimsy? The ridiculousness of stacking stones for Investiture and spirits liking TV romances or whatever it was seems like a Whimsy planet.

Yumi's planet was created by 

Quote

Virtuosity

I feel like this was confirmed in text, but can't remember the specifics. 

 

On 12/12/2025 at 6:41 PM, WestwardWind said:

1, it’s Ashyn. I know this isn’t very strong, but certain things seem to interlock in ways I can’t ignore. The fire in the sky, the war, and the king betrayed. This sounds similar to the story we hear in Stormlight about Ashyn. The plague is also suspect, because what we have of Above the Silence Prime, it sounds similar.

I do think Ashyn is an interesting possibility just because we know Brandon has been wanting to write about Ashyn for a while. There are a few roadblocks, though

This plot sounds drastically different from what we know about Silence Divine.

Quote

coltonx9

How are the floating cities in Ashyn held aloft?

Brandon Sanderson

By local magic... So basically, I can tell you how it works, because I'm not saving any secrets here.

One of the diseases gives this power. The reason it's called The Silence Divine is right now, the way I've devised it, is this power also causes hearing loss. So you have this virus that does this weird thing, but also gives you the power. And so there's a conclave of them, a chorus of them that keep the cities aloft. And that's why the book, if or when I write it, I guess it can't be a virus in this case. Whatever disease they have, someone develops penicillin and can potentially cause the city to come crashing down. That was the premise for me, but that means it needs to be a bacteria, not a virus but it needs to be a bacteria that stays with you long, so I have to work out exactly how I would make these diseases work.

Idaho Falls signing (Dec. 29, 2018)

Although Brandon does mention struggling to make the science work, so maybe this was a pivot to avoid that issue.

I think Mythos is the most likely or maybe Vax?? There's actually a (tenuous) link between Vax and diseases which I found surprising

Quote

LeftImBorn (paraphrased)

Is Vax a good place to get vaccines?

Brandon Sanderson (paraphrased)

*laughs* The place where Vax would be is not at a place where vaccines have been developed.

Dragonsteel Mini-Con 2021 (Nov. 22, 2021)

 

[Verdance he/him]

On 4/18/2026 at 3:32 PM, We_need_more_sel said:

I think FoD will take place on either; Ashyn

Ashyn was described as a disease Investiture planet by Sanderson. Opening chapters have two major diseases December's and the plague.

Or Sel because the demon river Investiture is part of the land or something. Also the Dor is the only source of Investiture we know of with enough power to use Fourtune visions on accident I think.

Or ancient Dhatri because the river seems like aethers. It is described as dark and oil like so maybe the "prophet" contained the demon keeping it from gifting the aethers to create aetherbound because they saw Midnight Essence as too dangerous in the future. The sword could also prevent anyone else from using that demon's aether.

Random thought is yumi and the nightmare painter maybe set on a plant created by Whimsy? The ridiculousness of stacking stones for Investiture and spirits liking TV romances or whatever it was seems like a Whimsy planet.

Spoiler

As an artist I agree that stacking stones the way Yumi is described to would 100% be an art form, and if I was a spirit, K-dramas would be enough for me to bestow magic on humanity, as well. I don’t think it’s confirmed that Virtuosity created the planet, I don’t see a lot of examples of single Shards creating entire planets, but she may have intentionally invested a pre-shattering planet the same way Honor did, or maybe it was completely accidental after she splintered herself. We just don’t know enough about Virtuosity (or Whimsy, for that matter) to say so, without getting into really crazy speculation, in which case I would refer you to @PanLin because they are smart and know things.

Uh Yumi spoilers, general cosmere spoilers

Edited April 20 by Verdance

[PanLin they/he]

6 hours ago, Verdance said:

We just don’t know enough about Virtuosity (or Whimsy, for that matter) to say so, without getting into really crazy speculation, in which case I would refer you to @PanLin because they are smart and know things.

Gosh, my first recommendation, thanks  although now I have to live up to it...

Side note, but I really love how these secret projects give Sanderson the opportunity to write Cosmere books with a different voice/style than the core books.

As usual, I got carried away and wrote a much longer post than I intended. Apologies!

 

On 12/13/2025 at 1:41 AM, WestwardWind said:

Alright. We received the first chapter today, and immediately I began to wonder “What planet does this take place on?”

I made a bunch of notes as I read through the two chapters (which I really enjoyed, can't wait for the book), but a lot of them aren't relevant to this question, so I'll try to stay on track.

 

I think it'll be set on either Mythos, Bjendal or an entirely new planet that hasn't been mentioned at all yet. In order of likelihood, my money's on:

1. entirely new (maybe Valor's shardworld, and the 'time travel' (imagine me doing air quotes as I say that) is a glimpse into her Invested Art)
2. Mythos
3. Bjendal (travel being disrupted to the planet gives a nice excuse as to why everything here feels so isolated from the Cosmere, but then Hoid and December's mum both managed it so who knows. Maybe December's mum, if she was a worldhopper, had something to do with the travel being disrupted. I also try not to put too much stock in what rules Hoid follows and breaks, the sneaky little gremlin that he is)

 

Relevant WoB:

Spoiler

Questioner

What world does Fires of December take place on?

Brandon Sanderson

New world!

YouTube Spoiler Stream 7 (Dec. 19, 2025)

It's unclear whether that means brand new, or a planet that's been mentioned but not seen in-text yet.

 

Firstly, the linguistic nerd in me thought the place names (Riverside and Mountaincrest) might hold a clue, as Hoid is clearly translating actual proper nouns (it'd be like referring to Belarus as 'White Russia'), but:

• there are so many potential place names with 'river' in the name (same irl) that it'd be a bit of a needle in a haystack
• afaik (please correct me if I missed any!) there are no existing Cosmere place names with the same etymology (like Streambank or Edge-of-Channel or something)

I even went through all the aons, but there aren't any known locations on Sel with 'Eno' (the aon for 'water') in the name, and the other aons we know are too tangentially related to 'river' to consider.

 

The WoB I quoted disqualifies most planets, so I'll just do a quick debunk of all the other planets that have at least been mentioned:

Ashyn

On 4/18/2026 at 8:32 PM, We_need_more_sel said:

Ashyn was described as a disease Investiture planet by Sanderson. Opening chapters have two major diseases December's and the plague.

On 12/13/2025 at 1:41 AM, WestwardWind said:

1, it’s Ashyn. I know this isn’t very strong, but certain things seem to interlock in ways I can’t ignore. The fire in the sky, the war, and the king betrayed. This sounds similar to the story we hear in Stormlight about Ashyn. The plague is also suspect, because what we have of Above the Silence Prime, it sounds similar.

'disease' immediately rings Ashyn bells, but, as others have noted, it sounds too far removed from what we know of Silence Divine for this story to be related to it. Also, the disease (singular; I'm not counting December's infertility as a disease in this sense without knowing more about her and her heritage) doesn't appear to have any positive side effects that might imply it comes from that Invested Art.

I do think there might be an Invested source to the disease (potentially the demon), as it strikes very precisely, ignores December completely (part of the reason I think 'somewhere far away' implies her mum was a worldhopper), and kills exactly one tenth of the population (we've seen afflictions affecting a specific number of people for a specific purpose before with Preservation).

The disease killing one in ten people also sounds a bit Rosharan, but that isn't a new planet so 

 

Braize

Just included this for completion. It's sort of a new planet but sort of not, but regardless, there's nothing in the worldbuilding in these chapters that includes any reference to singers, Odium, immortal Invested souls, or anything else that would point to Braize.

Even if this story is set way in the past, we've seen no reference to the weirdness or 'original purpose' that Braize exhibited before the Shards got there, and we know that Braize wasn't inhabited before then. Plus, Hoid is here, which at least implies this is after the Shattering.

If it's set so far in the future that Braize has humans living on it, then all bets are off and this entire post is redundant.

 

Obrodai

It's unlikely that Hoid would visit this planet without some sort of disguise after the warning he received, unless this book is set in the past—that same warning mentioned Hoid shouldn't return, meaning he's been there before.

There isn't really enough in these two chapters to support or discredit the idea that an avatar of Autonomy is here (maybe it's the demon ).

 

Vax

7 hours ago, Atlas333 said:

maybe Vax?? There's actually a (tenuous) link between Vax and diseases which I found surprising

Seems super unlikely purely for the fact that there is no mention of non-humans here. It could be that the peoples of Vax are quite segregated, but the existence of people with mixed heritage implies otherwise:

Spoiler

jofwu

Starling said Ed has Vaxilian heritage, but there's also a callout of "true Vaxilians". Does Ed have "true Vaxilian" heritage?

Brandon Sanderson

Yes. He's not full, he's mostly human.

YouTube Spoiler Stream 7 (Dec. 19, 2025)

I did consider whether Eddlin might shed some light on Vax and its likelihood for this story, but tbh as a worldhopping arcanist, I don't think much about him can be considered 'typical' of a native Vaxilian.

 

Yolen

On 12/13/2025 at 1:41 AM, WestwardWind said:

2. It’s Yolen. Mostly based on the fact that the king was murdered by one of his dukes. This is very similar to the tale of Jerick told to us by Hoid in Stormlight 5

It would have to be set WAY in the past (or future, I guess) for the tech level to match up. Also, no mention of dragons (maybe the demon is actually a dragon ).

 

That pretty clearly just leaves Mythos and Bjendal, which we know basically nothing about, or an entirely new planet that hasn't even been mentioned.

Let me know if I missed any other candidates!

 

On 12/13/2025 at 1:59 AM, Through the Living Sherma said:

non-spoilery: it takes place

in the spiritual realm

Speculation ahoy!

This is a fun tangent; we know that time travel will never be a thing in the Cosmere, which leaves a few theories:

1. the memories of those 6 decades didn't actually 'happen', and December actually received a super in-depth vision of one particular future that might have happened
2. her new life is technically in a sort of simulation, like what happened on Komashi
3. her new life is all happening in a version of her planet that was moved to or recreated in the spiritual realm, like Kharbranth

The third option doesn't really account for the 'time travel' in itself, and I don't think Sanderson would pull an 'it was all a dream' on us with the second option, so I really think it might be the first one.

Either way, it's super weird and is likely the result of either direct intervention from a super-Invested being, or a new Invested Art. I genuinely could see it being Valor's. The method of acquiring an Art is more related to its Shard than the stuff you can do with it; maybe one of Valor's Invested Art abilities is gaining knowledge of the worst possible future thread your life might take in order to try to prevent it, and is gained simply by being as incredibly lonely as December is described as being at multiple points, along with an inherent sense of justice and doing the right thing (plus maybe some inherent Connection to Valor, like we see from Preservation, Endowment, and Devotion/Dominion).

What's happening with December has given her far too much specific knowledge of the future to simply be an increase in Fortune, but maybe this story will show how Hoid got access to his Fortune abilities?

Edited April 20 by PanLin

[Through the Living Shadow he/him]

alright guys I was summoned back here

bc I have other things to do, imma say the things that I have been mulling over without really looking at other peoples posts

I apologize in advance for that. Except when you’re reading this, it won’t be in advance because I’ll already have said everything.

 

Some things that might be true:

1. The story takes place entirely in the SR. Elaboration:

Spoiler

There are a few things that make me think this.

First: Similarities with other stories. It’s been pointed out (by the post above) that there are significant similarities to the Dragonsteel, which is a very very cosmere significant history. As such, it could be reflected in the SR

Second: Weird magic. The magic definitely feels a bit softer, and the mechanics behind the river of blood feel a little sketchy.

Third (the obvious): “Time travel”. It’s either partly SR (visions), or fully SR.

2. Shardic influence / who is that Demon?

Spoiler

I have a few suspicions. It ties into the SR theory.

First: TOdium—specifically an SR construct representation of Odium. I explain this later.

Second: Valor. There were a number of elements that reminded me of Valor’s intent, and we know that Valor has been “hiding”, vanishing even from the other Shards. I’ll get more into this, but Taravangian, when he wants to keep Kharbranth secret, places the city in the Spiritual Realm.

Third: Autonomy. A few theories think that the demon and the demon slayer are the same person, this is consistent with the pattern that Autonomy has shown.

3. General speculation:

Spoiler

 

Weird stuff happens in the Spiritual Realm. And a lot of it is connected. There are only two instances of organized structures within the spiritual realm, and the Realm actively fights against this, collapsing into the chaos that the Bondsmiths in WaT have to order to turn into visions.

The older instance is the Dragons. They have their own place, the Spirit Shores, in the Spiritual realm, I don’t know much about it except that there’s a lot of power that goes into it. Enough to keep it up.

 
 
The newer, more hasty version of this is Todium’s city. The city was created in an instant, and is a very large city with a whole bunch of people not contributing to the power that keeps it a thing.

I don’t doubt that TOdium can keep it up, but I do doubt that TOdium can keep it stable. The spiritual realm may get real strange real quick due to this.

That said, I think that there’s a good chance that this story takes place far into the future of Kharbranth, perhaps even after Retribution is neutralized. That prompts two possibilities!

1. TOdium is reflected by the Spiritual Realm after he dies. This means the “Passion” part of him could be the Demon, and the demon slayer could be his “Logic”. He could even be Kharbranth, inhabiting it after he dies or smt.

 2a. Valor is the Demon. Valor is sometimes thought to be the fourth Shard of Roshar, which explains her involvement if the city is Kharbranth, but I doubt that she’s linked that way.

2b. Valor is December. Um. Yeah. I’m done writing now.

 

[Schizoposting]

Given that December is a healer who helps the sick and needy, even when she despises (like when she cared for Bark when he was sick), I think that there's a strong thematic reason to think that this is Mercy's world, especially since the demon would (presumably) require vast quantities of investiture, only available on a shard world. It also cannot be Valor's world (which is likely Mythos), because there are no dragons in FoD. And Whimsy, obviously doesn't make sense.

Judging from the other secret projects, the name of the world will be entirely new to us.

[PanLin they/he]

On 4/21/2026 at 4:35 AM, Schizoposting said:

It also cannot be Valor's world (which is likely Mythos), because there are no dragons in FoD.

There aren't any obvious dragons on Roshar, but Cultivation Invested it anyway.

I take it back! My bad, was clearly just a few days out of date on my WoBs  thanks for linking it, @Schizoposting

Edited April 22 by PanLin

[Schizoposting]

4 hours ago, PanLin said:

There aren't any obvious dragons on Roshar, but Cultivation Invested it anyway.

According to WoB, Valor's world has "lesser Dragons":

Spoiler

Questioner

...influences. I've heard you speak about Anne McCaffrey a lot. That's my second favorite book. 

Brandon Sanderson

Yeah. Criminally under-read these days. Anne McCaffrey's amazing. Her prose is so—those old-school writers, like Robert Jordan and Anne McCaffrey, they just had a way with words. 

Questioner

Yeah, it's fantastic. And I was wondering if there are any areas in the cosmere and your other novels, wherever, that the Anne McCaffrey books had influence or [you] got inspiration from [them].

Brandon Sanderson

We're going to—I've told people before, so it's not a huge spoiler—there is a planet with straight-up Anne McCaffrey-style dragons, right? Just [like] how the Shards that were human created human populations, or things like that, there is a Shard that has created—you might call them lesser dragons.

Dragons in the cosmere, a lot of them are going back to the ancient Eastern lore of the shape-changing deific sort of things; the same lore that ended up inspiring some D&D and things like this. They are powerful shape-changing beings that are immortal. There are also "these are cool dragons that we ride around on and have human-level intelligence, but [are] not immortal" and things like that. And we will get there eventually. I couldn't not do it. I've been waiting until I finally get a place to write that story. 

Questioner

Awesome, thank you. *applause from audience*

Brandon Sanderson

And you might, if you're a cosmere lore expert, know which dragon that is. And it is somebody who does not want to be found.

JordanCon 2026 (April 17, 2026)

 

[Frustration]

2 hours ago, Schizoposting said:

According to WoB, Valor's world has "lesser Dragons":

  Reveal hidden contents

Questioner

...influences. I've heard you speak about Anne McCaffrey a lot. That's my second favorite book. 

Brandon Sanderson

Yeah. Criminally under-read these days. Anne McCaffrey's amazing. Her prose is so—those old-school writers, like Robert Jordan and Anne McCaffrey, they just had a way with words. 

Questioner

Yeah, it's fantastic. And I was wondering if there are any areas in the cosmere and your other novels, wherever, that the Anne McCaffrey books had influence or [you] got inspiration from [them].

Brandon Sanderson

We're going to—I've told people before, so it's not a huge spoiler—there is a planet with straight-up Anne McCaffrey-style dragons, right? Just [like] how the Shards that were human created human populations, or things like that, there is a Shard that has created—you might call them lesser dragons.

Dragons in the cosmere, a lot of them are going back to the ancient Eastern lore of the shape-changing deific sort of things; the same lore that ended up inspiring some D&D and things like this. They are powerful shape-changing beings that are immortal. There are also "these are cool dragons that we ride around on and have human-level intelligence, but [are] not immortal" and things like that. And we will get there eventually. I couldn't not do it. I've been waiting until I finally get a place to write that story. 

Questioner

Awesome, thank you. *applause from audience*

Brandon Sanderson

And you might, if you're a cosmere lore expert, know which dragon that is. And it is somebody who does not want to be found.

JordanCon 2026 (April 17, 2026)

 

And we've seen less than 1% of the planet in only a few chapters. Chasmfiends hadn't even shown up this early in WoK.

[Schizoposting]

1 hour ago, Frustration said:

And we've seen less than 1% of the planet in only a few chapters. Chasmfiends hadn't even shown up this early in WoK.

In the WoB, Brandon literally says that he has not gotten around to writing the story about lesser dragons. So, this obviously precludes December's world from having them.

Edited April 21 by Schizoposting

[Frustration]

12 minutes ago, Schizoposting said:

In the WoB, Brandon literally says that he has not gotten around to writing the story about lesser dragons. So, this obviously precludes December's world from having them.

Just because the story doesn't contain them doesn't mean the world doesn't.

It's heavily implied that there are dragons on Nalthis for example.

Not that I'm trying to say that it is Valor's world, because I believe that it isn't. I'm just saying we can't rule out the possibility.

Edited April 21 by Frustration

[Schizoposting]

3 hours ago, Frustration said:

Just because the story doesn't contain them doesn't mean the world doesn't.

It's heavily implied that there are dragons on Nalthis for example.

They've been known to seed legends in various cultures, like the Bene Gesserit, so the mere cultural knowledge of dragons does not necessarily mean their current presence. And ones that we are talking about, aren't true Dragons anyway.

3 hours ago, Frustration said:

Not that I'm trying to say that it is Valor's world, because I believe that it isn't. I'm just saying we can't rule out the possibility.

Well, anything is possible, but some things are far more likely than others. From a thematic perspective, Mercy would make far more sense as the shard of December's world than the alternatives. 

Ultimately what a lot of people in the fandom forget to take into account (and I'm not necessarily accusing you of this), is that Brandon's decisions as a writer, are motivated the principles of good storytelling and writing. A lot of bad theories fail because they don't consider this. (Although he has made his fair share of bad decisions, like the Chanarach reveal—I am not a very big fan of reducing everything to petty interpersonal drama.)