When Rebecca Yarros announced Threshing Day while fans eagerly waited for the fourth book in The Empyrean series, many accused it of being a “cash grab” or an attempt to keep readers hooked on the world.
However, anyone who has managed to get their hands on the companion book after its release on September 29 can say that it is not quite the case, provided they have already read Fourth Wing, Iron Flame, and Onyx Storm.
Threshing Day gives us POV stories from 13 main characters (other than Violet Sorrengail herself, whose POV we already read in Fourth Wing) about their Threshing Day, the brutal, high-stakes trial in which the cadets of Basgiath War College bond with the dragons that choose them.
Yarros has said in promotional interviews that Threshing Day isn't a mandatory read, and that any reference needed to understand the fourth (or fifth) installments of the series will be included in the respective books. However, she has also said it is a book whose accounts we can fully trust, implying the other books are not, since they are technically in-universe historical records.
It is important to note that the main books of the series are a) from Violet’s POV, who doesn’t have all the knowledge and has previously been described as an unreliable narrator by Yarros, and b) supposedly “transcribed from Navarrian into modern language” by the scribe Jesinia Neilwart.
The fandom believes, and I agree, that Threshing Day is dotted with hidden clues about the future (and sometimes past) of the characters for those who like to dabble in theorizing. Now, let’s get all Sherlock Holmes about it. Here are some of the theories Threshing Day (nearly) confirms and some questions it raises, but doesn’t answer.
1. The dragons are lying through their (very sharp) teeth about some things
Yarros has hinted on multiple occasions that we have no reason to believe that the dragons are always being truthful, even to their riders.
We've already seen this with Tairn keeping the truth about the venins from Violet. There is a distinct possibility that the dragons of some of the other riders who eventually side with the marked ones and fly to Aretia, such as Dain Aetos or Rhiannon Matthias, also knew but kept the truth from them.
The dragons’ penchant for lying becomes far more evident in Threshing Day.
Garrick Tavis’ Brown Scorpiontail dragon, Chradh, is recorded in Professor Colonel Valin Kaori’s The Compendium of Dragonkind as a 27-year-old dragon with no previous riders. But when Garrick bonds with him, he notices that Chradh has a deeper, older voice and many scars on his wings, suggesting he has seen battles.
Imogen Cardulo’s POV makes an even better argument for this theory. She recognizes her Orange Daggertail, who is supposed to be only 19 years old, as the dragon she saw as a child bonded to her grandmother. Her name is definitely not Glane, which is what she is recorded under, and she has likely killed many (Humans? Gryphons? Venins?) in battle.
At the beginning of the book, an advisory on Threshing Day by one Colonel Thadeus Palme says that “no artist has flawlessly depicted every distinguishing mark of a dragon, which makes telling descendants apart woefully difficult.”
The only way Navarrians can visually identify dragons is through keen observation during flight maneuvers, and the only way to know their names and ages is through their riders, since no one can speak to a dragon they aren’t bonded to.
2. There is a rift within the Empyrean, and we’re not sure who’s on which side
It becomes quite obvious that some dragons “waited for” the marked ones, the children of those who participated in the Tyrrish rebellion, and, whether out of self-interest or not, are empathetic to the cause of fighting venin.
It is also very likely that all or most of the marked ones’ dragons were once bonded to their ancestors and thus have (at least) two signets. We know Xaden, Garrick, and Imogen do, and Liam might have had too.
This targeted bonding strategy shows that a faction of the Empyrean is intentionally building a powerful, rebellious military force right under the noses of both the Navarrian leadership and the conservative dragon elders, such as General Melgren’s bonded and the leader of the Empyrean, Codagh.
Now, this could simply be an ideological rift over the venin situation, or, as a popular internet theory claims, some of the dragons are, simply put, not good guys.
In Fourth Wing, we learn that the collection of dark fables about venins that Asher gave to Violet “warns against the lure of magic” and “demonizes dragons.” The book has been right about the venins, so what’re the chances it totally got the dragon part wrong?
3. Some dragons are against Navarre
This brings us to the next point: at least two dragons openly express disdain for Navarre and its systems.
Imogen’s dragon, Glane, hates Navarrians with a fierce passion that likely predates the Tyrrish rebellion. When Xaden says that he wants to burn down Basgiath, Sgaeyl agrees enthusiastically.
In Fourth Wing, we were told the whole point of Empyrean bonding with Navarrians was mutual benefit, and that the dragons sought humans out to help ward the country against Poromish attacks. But we were obviously lied to.
Now we know that the venins are the real enemy, but it still doesn’t explain Glane and Sgaeyl’s intense fury at Navarre.
One explanation could be that they viewed the Navarrian isolationist policies that left Poromiel to fend for itself as cowardly and inhuman. Another could be that Navarrians betrayed and endangered certain dragon bloodlines in the past.
The Vale in Basgiath isn’t the only known hatching ground. Aretia, for example, was a hatching ground for black dragons in the past. It could be that when the
4. All the cadets are injured before they bond, and it could be about bloodlines
In all 13 POVs, the characters get injured in one form or another before they climb onto their dragon’s back.
Most of them get wounded either by accident or by another cadet and bleed. Those who don’t, the dragons do it for them. Sgaeyl herself gives Xaden the scar on his eye, and Violet’s sister Mira gets a talon dug into Mira’s thigh.
Some fans believe this is a tactic dragons use to check whether someone has already turned venin. I believe this could also be a way to determine their bloodline, since Threshing Day makes it pretty clear that dragons seek out individual cadets even if they aren't one of the marked ones.
Dain, however, is described as having only a welt on his hand from saving a second-year rider, Joelle Tadita, and later hitting his chin on his dragon Cath’s scales.
A welt doesn’t usually mean broken skin. However, in Fourth Wing, Violet spots a scar on Dain's chin hidden beneath his beard, so maybe he did bleed when he hit himself against his dragon's back.
Cath also says Dain’s only allegiance should be to him, and that this is the only condition of the allegiance they were forming. Between this and Sloane Mairi’s comment in Onyx Storm about his surprising amount of power, it makes one suspicious of what Dain and Cath are up to.
5. Brennan’s into men, which strengthens a popular Naolin theory
Brennan’s POV confirms that he is interested in men, as he mentions sleeping with fellow cadet Flynn Ennis a few weeks earlier.
It strengthens the existing theory that Naolin, the previous rider of Tairn and the siphon who gave his life to save Brennan, was his lover.
Naolin happens to be one of the most mysterious characters in the series. Both Tairn and Brennan refuse to speak about him. In a series where bloodlines and legacies are clearly important, we don’t know his full name.
Another popular theory says Naolin is an ancestor of the Sorrengail kids—maybe a grandfather or their biological father—which would explain both the sacrifice and Violet getting two signets. Some also believe that he turned into a venin in his attempt to revive Brennan, or “play God,” as Kaori labeled it.
6. Asher Sorrengail has secret powers
Asher is a scribe, and scribes are not allowed to enter the Threshing arena.
Yet he not only enters, talks to his son at length, and shows no signs of distress at someone possibly being killed by a dragon at a distance, but also says that a dragon is the “greatest gift a god can give” and then disappears into the forest that he had no business being in the first place.
Seconds later, Brennan sees a brown dragon take off into the sky.
Now, it could just be any dragon roaming around the forest, seeking to bond with its rider and charring everyone else. It could also be that Asher himself has a dragon, which would explain how he traveled long distances for his research.
A third, funnier option is that Lilith’s dragon, Aimsir, who was also brown, gave him a lift to the forest. But dragons are not known to carry anyone other than their riders. Tairn and Sgaeyl have, on a couple of occasions, claw-carried Xaden and Violet, respectively, but not on their backs.
One theory suggests that if Violet has bonded with two dragons, then maybe a dragon can bond with two humans as well. It’s safe to say that literally anything can happen, since humans know little to nothing about how the Empyrean actually works, and we, the readers, only get to know what Violet knows.
7. Asher gave Brennan a bracelet similar to what Mira was wearing
Before Brennan heads to his Threshing, Asher gives him a black beaded bracelet as a gift. Moments before, Brennan smells parchment on Asher.
In Onyx Storm, Mira wears a similar bracelet that Violet identifies as made of tourmaline and also smells parchment as Mira rotates it. Brennan later recognizes it as belonging to their grandmother Niara, Asher’s mother, who lives in Luceras.
We don’t know much about Asher’s family, but Niara cut ties with her son and daughter-in-law after they seemingly dedicated Violet to the Goddess Dunne on the island of Unnbriel.
Brennan and Mira get into a huge fight over Mira visiting Niara, because she apparently “hated” their parents.
We don't have clarity about the bracelet—whether Mira’s is the same one Asher gave Brennan, or why it always smells like parchment when the beads are rotated.
Some fans believe that it could be the missing pages in Lilith’s journal, or more pages from Warrick’s journal, who was one of the original six riders, and also from Luceras.
8. Violet’s family had fire and water wielders
In Mira’s POV, Teine says that her grandmother wielded fire and her great-grandfather could control tides. We know that Lilith Sorrengail comes from a family of legacy riders, but we don’t know anything about her mother or grandfather.
But we do know Grandma Niara.
Some people also believe that the Colonel Daxton mentioned in Onyx Storm epigraphs is actually Niara, which would make her a rider. Ashton took his wife’s surname after marriage and maxes out as Lieutenant Colonel Asher Sorrengail in the book.
It’s hard to know which grandmother Teine is talking about, and Mira asks no questions either, but it could very well not be on Lilith’s side.
On Threshing Day, there’s only one rule: don’t die.
— Waterstones (@Waterstones) September 29, 2026
The deluxe first edition of Threshing Day by Rebecca Yarros, featuring stunning silver-gilded edges, illustrated endpapers and 16 full-colour illustrations by artist Joe Requeza is here: https://t.co/40oBY2UwII pic.twitter.com/Fn5uLKvEZH
9. Dragon’s colors are connected to the gods
Onyx Storm floated the theory that the six gods of this world are connected to the six dragon colors, and Brennan’s POV helps build on that.
Zehyllna, the island of Zihnal, the god of luck, had several orange elements.
When Brennan bonds, his Orange Daggertail, Marbh, calls himself “Zihnal’s Chosen.” Earlier, Brennan and Asher were also talking about Zihnal and his gifts. Orange dragons are temperamental and unpredictable, much like luck itself.
In his POV, Garrick says Dunne, the goddess of war, “favors Xaden in a way she never blessed his father.”
Xaden’s dragon is blue, the color worn by Dunne’s followers on Unnbruiel, and Sgaeyl is famously known for being a literal embodiment of war. Other blue dragons are fierce and combative, too.
On the other hand, the irids are, as the name suggests, iridescent, showing a rainbow of colors that shift when seen from different angles or in different light. They don’t really have a single shade. It could mean that the irids are either connected to all the gods, or none of them.
10. Colonel Aetos can manipulate via touch
Colonel Aetos turned out to be the antagonist that readers thought Dain would be. But aside from the fact that he’s despicable and was Lilith's aide, we don’t know much about him. We don’t even know his first name.
But he is a rider and has a dragon, which means he has a signet.
In Threshing Day, we get a glimpse at how the colonel manipulates Dain to spy on the marked ones, and eventually Violet in Fourth Wing. We knew Dain’s intentions weren't to cause harm and that he was only doing his father’s bidding, but reading about his equation with the colonel makes it even clearer.
When Colonel Aetos asks Dain to tell him if the marked ones break Codex, he argues back at first, pointing out that the chain of command would handle it. But the colonel pushes the point, gripping Dain’s shoulders hard as he convinces him to do so.
This has led to suspicion that Colonel Aetos can manipulate people’s minds through touch, raising the question of how often he has done it, and to how many. Did he ever try it on his boss, Lilith?
Being able to change another’s mind is an extremely dangerous signet, especially for someone in his political position with his personal ideologies.
11. The rebellion relic addendum
Fourth Wing says Addendum 5.2 dictates that no more than three marked cadets can be assigned to one squad, and then Addendum 5.3 forbids them from assembling in groups of three.
Many readers assumed it was a typing or editing error that the number of marked ones allowed together went down by one without explanation. However, Threshing Day reiterates the point as written, and the inclusion feels deliberate.
In Xaden’s POV in 231 AU, Kaori mentions that he usually doesn't get to speak to more than three marked ones at the same time. In Dain’s POV in 232 AU, his father gets mad at Bodhi Durran for giving a pep talk to three other marked ones, and reminds his son about the new rule made that year.
We know these rules relate to Melgren’s signet of battle foresight and the rebellion relics that let the marked ones circumvent it.
It is possible that Xaden killing Prince Alic in the presence of Garrick and Masen and getting away with it (with help from Sgaeyl, who burned the corpses) prompted the rule change. It is also possible that something else forced Addendum 5.3.
12. Dragons can bond with riders even before Threshing
In hindsight, it’s not that unbelievable. Dragons can do whatever they want, clearly. But since we didn't know about it, Imogen’s story came as quite a delight.
19-year-old Glane, who is most certainly neither 19 nor Glane, claimed Imogen right after Presentation Day, when cadets walk through the valley while dragons take a look at their picks for the year.
She went to bed with a relic of an Orange Daggertail snaking around her waist. By the time Threshing Day came around, she had developed the mental pathway that allows bonded dragons and riders to speak internally.
None of the other characters went through this, but we've already seen dragons decide who they want before Threshing Day and convey it through the senior marked ones. Xaden gives the message to Bodhi, Imogen to Sloane, and so on.
13. Chradh and Sgaeyl don’t get along
In Imogen’s POV, Garrick shows up to pass along the message that Glane has bonded with her, although she didn't need a heads-up.
But because he does, we learn that Sgaeyl and Chradh “rarely agree on anything.”
Given that Xaden and Garrick are so close, it is a bit strange that their dragons don’t get along. It could be a hint at something to come in the next book. Or it could just be that Chradh is old and cranky, and Sgaeyl doesn’t get along with anyone.
14. The petrified oak tree
The oak tree mentioned in Imogen’s POV, where she finds Quinn, seems to be connected to two references.
One is that a lightning wielder split the tree in half “ages ago.” Since everything in this series connects to its historical lore, and one of the original six riders possibly wielded lightning just as Violet does, this seems like an important point to note.
Whoever the wielder was, why would they split a tree near Basgiath in half? Was it an accident? Was it because of a battle? Did they channel from the ground, become a venin, and attack the dragons on Threshing Day? Maybe we’ll find out.
Second, when Imogen, Quinn, and Garrick hide behind the oak tree from Glane’s fire, Garrick points out that the petrified tree saved them.
Now, a tree doesn’t get petrified because of lightning. Wood becomes petrified when inorganic minerals replace the organic material over millions of years, turning it to stone and making it a fossil.
That raises the possibility that Imogen manifested her stone-manipulation signet to protect the two, having already bonded two days earlier. If so, this isn’t really a reveal, since we already learned that Imogen can manipulate earth as her second signet in Onyx Storm, but it's a fun little insight into the character nonetheless.
15. Sliseag was not “available” for Sawyer
Not getting to bond in his first year at Basgiath left Sawyer Henrick drowning in self-doubt and self-loathing. Next year, his dragon Sliseag very calmly informs him that he wasn’t “unworthy” the last time, but he “simply wasn’t available” to bond.
While that soothed Sawyer’s spirit, it baffled readers.
Sawyer previously says that Sliseag’s last rider died the year before last. Technically, he should have been available to bond last year.
Maybe the answer is as simple as Sliseag resting and recovering from the loss. But as we have seen time and again, dragons lie and keep secrets. So this could connect to something else we discover later.
16. Can a cadet turn down a dragon?
We don’t know the right answer, because it is practically unheard of. Who would say no to a dragon, and at what cost? More importantly, why? It’s considered the greatest gift in the entire Continent.
But what if someone wants to say no to bonding with a dragon? Can they?
But when Sliseag asks Sawyer to choose between climbing up to take his seat or going to help Trina (who was probably beyond help after falling from her dragon), he says something that hints cadets may have a say in the matter.
“I am not the only one with agency here, but I approach the limits of my patience,” Sliseag tells Sawyer. Just before this, he also tells Sawyer that he will not attach himself to another rider who cannot adapt to loss.
Makes you wonder what happened to his last rider. Did they lose themselves in the grief of someone’s death? Did they set off to take revenge, or worse, break the dragon bond and turn venin? That would explain why Sliseag needed a year to recuperate.
17. The “gift” Sloane receives from her Rune Master mother
Sad as Liam and Sloane’s chapters are, both dragons mention their mother with reverence.
Deigh calls her Rune Master Celadine, and Thoirt tells Sloane she inherited her mother’s gift, which Liam did not. Thoirt also tells Sloane that without her, they will lose the war.
We saw Sloane save the day twice in two books—first when she siphoned Lilith and Aimsir’s life force to raise the Basgiath ward stone, and second when she siphoned Dain’s power into Brennan, who then used it to mend Mira.
If you think about it, siphoning is practically channeling raw magic from a person or an object to another, similar to how a venin does, but without turning into one.
Fans have theorized that Sloane could be the so-called “cure” to being a venin that Violet is looking for to bring Xaden back, and that her mother was also looking for, though her reasons are unknown to us at the moment.
Sloane, using her siphoning, could draw directly channeled magic out of a venin and return it to the original source, and maybe even revive the object or person it was taken from. (It makes one wonder if that’s what Naolin was doing with Brennan, who had either turned venin or got drained by a venin.)
We don't know how runes play into this. In fact, we don’t know much about runes or how they work at all, mainly because Violet doesn’t know much about them.
But we do know that runes are strands of magic pulled from a wielder's power, woven into geometric patterns for specific purposes, then placed in an object for either immediate work or later use.
Liam and Sloane’s mother made the runes that created the rebellion relics in the arms of the marked ones. The runes were created to protect the children of the Tyrrish rebels from the signet of the rider who executes them, which turned out to be General Melgren, and thus the relic prevents Melgren from seeing the marked ones when they’re in groups of three or more.
18. What Aaric knows
Aaric has always come across as someone who knows more than he should and hides about 90% of that knowledge. His Threshing Day POV was no different.
He practically hunts down Molvic, the Blue Clubtail who allegedly is only 39 with no previous riders, instead of the other way round. He tells Molvic, “I am the one you have waited for, searched for all these years. I am the reason you have wandered the Threshing Valley unbonded.”
He also promises his dragon to fly for Molvic’s “kind” but not the “Empyrean that has enabled this travesty.”
For now, we can only guess he is talking about the complicity some dragons have shown toward the venin issue and how they went along with their riders hiding the truth for so long. But there is definitely more to it that we’ll find out in Book 4.
Also, I have a feeling that for once, it might actually be true that Molvic did not have a previous rider.
19. Garrick and Dain’s mothers
The Empyrean series is full of dead mothers and fathers. Almost everyone has lost at least one parent, if not both, especially the marked ones.
But Garrick got lucky. We don’t know if his mother fought in the rebellion, but he managed to get her out of Aretia before the Navarrians came to quell the “apostasy.” We don’t know where she’s now, or how Garrick alone pulled off such a feat at 17 while dragon riders actively hunted them.
We also don’t know where Dain’s mother is. She apparently left when Colonel Aetos was stationed in Luceras during the rebellion. Dain’s father swears it was because she inferred he couldn’t protect her from the rebels' wrath.
But who is out here believing anything Colonel Aetos says? He either doesn’t know the real reason she left and is making one up to console himself, or he DOES know and is lying to Dain. My vote is for the latter.
Now, whether she joined the rebels or simply went into hiding because she didn’t want to stand for the lie Navarrians were telling about the venins, remains to be seen.
20. Xaden’s new venin brother
The one question everyone wanted to know after Onyx Storm was who Xaden’s new venin “brother” was that turned during the Battle of Draithus.
Yarros has given us a few hints. She has said to look for who is missing or unaccounted for at the very end of the book, when Violet finds out she is now married to Xaden.
She has also said that it would be a character who feels like whatever they have been given or achieved is “not enough,” and that the underlying motivation and core of turning venin always ties back to power.
Naturally, fans have dissected the Threshing Day chapters of all the potential candidates—Garrick, Bodhi, Brennan, and Aaric—to understand who best fits the description.
Brennan’s doesn’t really offer much, because his Threshing happened nearly a decade ago, and a person changes a lot in that time.
In Xaden’s chapter, Garrick tells him, “Misery loves company, and you and I will sail those melancholic waters like we do everything else—together.” This could be a foreshadowing of Garrick following Xaden into his venin era, as he has always done before, or it could just be Garrick trying to cheer themselves up before Threshing.
Threshing Day presents Bodhi as the most suitable contender, as he rants quite a bit about being in Xaden’s shadow. It gets to the point where Bodhi laments that Xaden has better hearing than him. The amount of insecurity Bodhi feels about Xaden being everything he isn’t, even though they are almost like brothers and even look kind of similar, is sad, hilarious, and suspicious at the same time.
Moreover, his dragon Cuir tells him, "I will choose you every day until your death or demise." Bodhi wonders if both words mean the same thing, making us wonder if "demise" here points to his turn to the dark side.
Bodhi then promises to choose Cuir "over everyone," and Cuir orders him to "remember that vow." This could hint that Bodhi channeled from the ground to save Cuir from Berwyn at the end of the Battle of Draithus, similar to how Xaden did for Sgaeyl.
In addition to the clues for Book 4, Threshing Day also does a marvelous job of giving more context to a few interpersonal relationships. We empathize with Dain Aetos a little bit more, as his complex relationship with his father is laid out, especially given the stark contrast between theirs and the other father-son conversation we see between Brennan and Asher Sorrengail.
We also learn that Imogen and Garrick aren't just flirting. They have been in love since childhood and refuse to act on it for complicated reasons involving death, like most other things in Basgiath.
Keep up with us at Winter Is Coming for more opinions and updates from the Empyrean series.
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