Threshing Day may be the first book I have watched cause a fandom argument before most people even understood what the book was. Impressive, really, if you think about it.
The important bit though is that Rebecca Yarros’s Threshing Day releases September 29, 2026. It is a collection of thirteen Empyrean stories built around riders and the dragons who chose them and? It is Empyrean 3.5. It is not book 4…it will not resolve the Onyx Storm ending. (Which frankly…what was that? I’m still in shock and need to know. And I have all the gossip on book 4 here)
The fantastic thing about this series to note though, is there are many conspiracies surrounding the idea that the dragons are really running the political show. And this book? It gives us the best bits. It’s all about the moment a dragon looks at a human being and decides, for reasons known mostly to dragons, yes, this idiot will do. And I’d bet my hat it has a ton of clues sprinkled in it to boot.
The short version
- Release date: September 29, 2026.
- Format: thirteen stories about Empyrean characters and their dragons.
- Series position: Empyrean 3.5 / companion collection.
- Approximate length: around 224 pages in early listings.
- Xaden and Sgaeyl: confirmed to appear.
- Deluxe first edition: sixteen full-colour illustrations by Joe Requeza; US and Canada while supplies last.
- Is it book 4? No.
- Does it delay book 4? Yarros says no.
What is Threshing Day actually about?
Threshing is the Basgiath trial where first-year cadets try to bond with a dragon. ‘Try’ is the word of the day here because the dragons choose really, at the end of the day.
That means this collection has a very cool premise. Take thirteen bondings, thirteen characters, and make cute little stories out of them. Xaden and Sgaeyl are already confirmed, squee!
Where to Order?
Why is Threshing Day not Fourth Wing book 4?
Because it looks backward, while book 4 has to move forward from Onyx Storm. Essentially, it’s a collection of short stories.
The retailer placeholder made this much messier than it needed to be, and everyone snooping didn’t help (cough, I totally wasn’t part of the problem). ‘Untitled Empyrean (Not Book Four)’ appeared for months, and was found in seconds. Which is hilarious. People assumed what we knew (book 4 was coming) would still be true. And it simply wasn’t it.
Book 4 remains the mainline sequel and the penultimate book in the planned five-book series. Threshing Day is a companion collection.
Which Threshing Day edition should you buy?
If you care about the art as much as the stories, the deluxe first edition is the obvious one to choose. It’s sixteen full-colour, stunning,, illustrations in a book. This short has a lot of art, and ‘while supplies last’ means if you want it, pre-buy it because it will go fast. I’m still undecided myself.
If you are here for the text which is almost always me, even sprayed edges don’t usually sway me, buy the standard hardcover, ebook, or audiobook. I’ll probs grab the physical for collection sake, and the audiobook so I can read while I work and do all the things.
International readers should also watch their local publisher rather than assuming the North American version will be available normally, because sometimes there are some nuances.
What do thirteen stories tell us about the structure?
Thirteen stories across roughly 224 pages means these are likely to be short, very short. That is good news if you expect emotional close-ups and bad news if you’re wanting something that really digs into the lore. It’s likely to be more puzzle-piecy, where you really have to pay attention to catch the gotchas later in the series that are bound to be sprinkled through here.
A compact bonding story is still a cute idea. It can focus on the decision. Who was this rider before the dragon chose them? What did the dragon see? What fear, flaw, loyalty, arrogance, grief, or tiny act made the choice possible? (Dying to see some of that from our faves). That is enough for a short story if the emotional beat is sharp.
Collections are uneven by nature. I expect at least a couple will be longer than others because they will be important to the story later.
Who will the thirteen stories be about?
Only Xaden and Sgaeyl are confirmed in the material we have. Which considering where Xaden is at post book 3…it’s got to be a set up to break our hearts.
The obvious other possibilities are riders whose bondings have been mentioned enough to create curiosity. Think Dain, Rhiannon, Ridoc, Sawyer, Mira, Brennan, and characters whose later fates would make a joyful Threshing scene actively cruel to reread. So yes, maybe even Liam.
And then there are the dragons we can choose from. Like, Tairn has history. Sgaeyl has history. Any dragon that chose before, refused before, or made a choice nobody understood has a story and we might get our hands on it. I’m sure there will be at least one of these as it’s a good twist.
Why this companion book probably earns its place
Companion books get side-eyed because readers get charged hardcover money for deleted scenes that should have been part of the story to begin with, and feel scammed. I think this is the perfect timing for this drop though, because it should give us extra clues for the rest of the story, as well as pull on heart strings. If this came out after book 5, then we might feel more cheated.
The great thing about these stories as well, as they are not simply a new POV/same scene scenario.
The risk is that explanations can shrink mystery. Sometimes it’s the gaps in the stories that our mind fills which make us feel personally connected to characters. For instance, Xaden and Sgaeyl’s bond has power partly because we do not know every inch of it and imagine it to be like Violets but with our own brain version of Xaden’s charm. Yarros is a good writer, and has probably considered all of these things and much more.
If you’re the kind of reader who loves all the clues check out Fourth Wing Book 4 | Everything We Know and Everything We Dread, The Wildest Empyrean Theories, and Onyx Storm Theories That Might Actually Be True.
How to preorder without getting burned
- Check that the listing explicitly says deluxe if the illustrations are the reason you are buying.
- Use a retailer with a preorder price guarantee where possible.
- Outside the US/Canada, follow the local publisher for regional edition announcements.
- Independent bookshops can be worth checking for limited allocations.
- Do not panic-buy a resale copy in release week.
What are the spice and content expectations?
The main Empyrean books contain explicit sex, injury, violence, and character death. Threshing Day is built around a lethal trial, so pretending this will be a cozy little dragon scrapbook would be optimistic. There will clearly be a bit of drama.
I would expect less spice than the mainline books because the stories are short and the bonding is the event.
Why Threshing is strong enough to carry a whole collection
Threshing has a lot of lore to spill. The whole rider system depends on dragons choosing humans, while the humans build an entire brutal institution around pretending they can prepare for that choice, when at the end of the day, it’s all dragons and we’re not entirely sure why they chose who they do. This book might open that up and explore it.
Every short story can ask the same question – what did the dragon see? – and give us a completely different answer than what we might expect from the kind of human environment we have been watching. It might even be surprising. Maybe the dragons don’t act in a way we have even considered yet.
Should you read Threshing Day before book 4?
Yes if you love character history, dragons, and emotional context. Probably not if you only care about advancing the main plot and the romance therein.
A 3.5 collection should not be required homework for book 4, because that would be an aggressive way to punish readers. But if you’re the kind of reader who likes to guess what’s next, and love character driven lore, then this is the book for you.
Where this leaves us
With an amazing book full of thirteen bondings. Xaden and Sgaeyl. Sixteen illustrations if you go deluxe. And a date…September 29, 2026. I am prepared to cry over a dragon choosing somebody we already know is doomed for a particularly painful reason on the dragon’s behalf. And while we wait here are some book recs to check out https://thegiltlist.com/books-like-fourth-wing/ and https://thegiltlist.com/romantasy-books-with-dragons-and-romance/. Or head over to the romantasy hub for some more.
Frequently asked questions
Threshing Day releases September 29, 2026.
No. It is an Empyrean companion collection positioned between the mainline novels. Book 4 is a separate sequel to Onyx Storm.
The book contains thirteen stories about Empyrean characters and their dragons, focused on the day those rider-dragon bonds formed.
Yes. Xaden and Sgaeyl are confirmed to be included.
The deluxe first edition includes sixteen full-colour illustrations by Joe Requeza and is planned as a limited North American first edition while supplies last.
No, according to Yarros. She has described the collection as a return to Basgiath while she continues work on book 4.
