Everything we know about 'Fourth Wing' book 4, from Rebecca Yarros' hints to new clues in 'Threshing Day'

• Rebecca Yarros brought readers back into her "Empyrean" universe with "Threshing Day."
• The collection of stories offers clues about the series' future, which ended on a cliffhanger.
• The author has also shared hints about how Violet Sorrengail's story will continue in interviews.

Rebecca Yarros' next "Fourth Wing" book is out, but it's not the fourth novel in the "Empyrean" series.

It's been over a year since Yarros released "Onyx Storm," which continues the story of Violet Sorrengail's journey to become a dragon rider and fight forces of dark magic at Basgiath War College after books one and two in the series, "Fourth Wing" and "Iron Flame." The series is set to comprise five novels, all published by Entangled's fantasy imprint, Red Tower.

"Onyx Storm" — the fastest-selling adult novel released in 20 years — ended on a cliffhanger, so Yarros' readers have been clamoring to get their hands on the next romantasy novel in the series since the moment they finished book three.

Yarros has confirmed on Instagram that she is writing book four, but it will still be a while before it's published. However, on Tuesday, Yarros released a collection of short stories set in the "Empyrean" universe, "Threshing Day," giving readers a taste of what the future of her series may hold.

Keep reading for a rundown of everything we know about "Empyrean" book four and how "Threshing Day" fits into the series.

Warning: The rest of this article has spoilers for the "Empyrean" series, including "Threshing Day."

Yarros started writing the fourth 'Empyrean' novel in March 2026

Yarros released the first three books in the "Empyrean" series in under two years. "Fourth Wing" came out in April 2023, "Iron Flame" was released in October 2023, and "Onyx Storm" hit shelves in January 2025.

Yarros made clear she wouldn't be writing book four at the same pace. Speaking at an engagement in Philadelphia on January 25, 2025, Yarros said she wouldn't commit to a release date, as she was planning to write a contemporary novel first.

Yarros latertold Ellethat she intended to rest before returning to writing in part because the amount of work she did in recent years wasn't good for her mentally or physically, as she has chronic medical conditions,including Ehlers-Danlossyndrome, a connective tissue disorder, andPOTS, an autonomic nervous system disorder.

She kept her word, keeping largely quiet about book four for the rest of 2025. Then, on February 8, 2026, she shared on Instagram that she had begun plotting, and on March 19, 2026, she posted a Reel announcing she had begun writing the next "Empyrean" novel.

In the Reel, Yarros walks up to a board and writes "#4" at the top.

"And now that my latest contemporary novel is off to my editor, I'm back writing in the Empyrean world for the foreseeable future," Yarros captioned the post. "Let's ride."

The author has posted a few updates about her progress since then, most notably on June 13. She shared a short video clip on Instagram of an ocean view and said in her caption that she would be spending the summer writing at the beach.

"Our home is undergoing distractingly noisy work, which gives us the perfect excuse to pack up our kids and spend the summer on Deverelli time while I'm writing book 4," she said. Deverelli is an isle that Violet visits in "Onyx Storm," and it plays a key role in the book's plot.

It will still be a while before the fourth "Empyrean" book hits bookshelves, but fans can rest assured that Yarros will be focused on the novel in the coming months.

The fourth book will hopefully address unanswered questions from 'Onyx Storm'

There was no shortage of drama at the end of "Onyx Storm."

First, Xaden took more power from the earth, speeding up his transition into a dark magic-wielding venin, one of the main antagonists in the series, and sending him down a path toward evil. Another unnamed dragon rider turned venin as well.

One of Violet's dragons, Andarna, returned to her after her time away with the irid dragons, and Violet woke up with a wedding ring and blessing of her marriage to Xaden from the goddess Dunne, with no memory of the last 12 hours of her life.

In the book's final line, her fellow rider Imogen Cardulo reveals she used her signet power to wipe Violet's memory of the night — at her request. Violet's brother, Brennan, also revealed that six dragon eggs and four riders, including Xaden and his best friend, Garrick Tavis, are missing.

Hopefully, the fourth book in the "Empyrean" series will reveal what happened between Violet and Xaden, where Xaden and the other missing riders are, the location of the missing eggs, what Andarna learned from her time with the irids, and how Xaden's additional use of his venin powers harmed his soul.

Likewise, Violet will likely still be searching for a cure to save Xaden from being venin, but as his wife, she also becomes the Duchess of Tyrrendor. She will have new power and responsibility in his absence, and readers will have to wait to see how she balances her new role as she develops her signets.

Hints from 'Threshing Day'

On September 29, 2026, Yarros released a new "Empyrean" collection called "Threshing Day." It tells the stories of 13 cadets at Basgiath as they bond with their dragons in the high-stakes, often life-threatening experience known as Threshing. Violet made history as the first rider to bond two dragons on her Threshing Day in "Fourth Wing."

Most of the "Empyrean" series is told from Violet's point of view, but Yarros said during an appearance on the "Fantasy Fangirls" podcast in October 2025 that she plans for the fourth installment to be told from multiple perspectives, including the character Sloane Mairi specifically. "Threshing Day" offers a bridge to those new perspectives, as all the featured riders are characters who could tell future "Fourth Wing" stories, like Sloane, Xaden, and Imogen.

The collection also addressed a plot device Yarros has used in the novels. After riders bond a dragon, the rider announces the dragon's name to the Scribes so it can be recorded, rather than the dragons communicating directly with the Scribes. Yarros previously said that creates the possibility that the dragons or riders are lying about their identities.

It is forbidden for riders to bond with their direct ancestors' dragons, as it allows riders to develop second signets. In the text, it appeared like some dragons wanted to bond with the children or grandchildren of rebels they had worked with in the past, skirting the rules. However, it wasn't clear how that worked until "Threshing Day."

In some cases, like that of Imogen's dragon Glane, the dragon pretends to be someone he or she is not, taking advantage of the fact that it is difficult for humans to tell dragons apart. For others, it is human lies that allow them to break the rules. Xaden's dragon, Sgaeyl, was able to bond with him because his grandmother lied about who his grandfather was.

Yarros also included scenes showing dragons specifically seeking out the rebel children, confirming that the dragons are invested in the fight against venin as well. Both Sloane and Xaden's cousin, Bodhi Durran, are told by their older peers during their Threshings that a dragon is looking for them, intending to bond with them in part because of their ties to the rebels.

"Threshing Day" offered further insight into who may have turned venin at the end of "Onyx Storm" as well.

Speaking at an event in Denver on February 2, 2025, Yarros advised readers to "pay attention to who's missing at the end" and "someone who feels like whatever they have given is not enough, which is always the case when you turn venin."

Bodhi, Garrick, and Violet's brother Brennan fit that description at the end of "Onyx Storm," and all three appear in "Threshing Day." Yarros seemed to foreshadow that Bodhi or Garrick, in particular, could have turned venin based on their behavior during their Threshings, with Garrick putting others before himself too often and Bodhi feeling like it is his personal responsibility to keep Xaden safe.

You can read more about the most important details in "Threshing Day" here.

Yarros shared some clues for book four while promoting 'Onyx Storm'

Yarros went on an "Onyx Storm" book tour after the book's January 2025 release, offering some insight into the series' future as she connected with fans.

At an event in Los Angeles on January 21, 2025, Yarros said, "Someone you love won't make it in book four." That comment isn't that surprising, as beloved characters have died in each installment of the series. However, Yarros got more specific with her hints as her book tour continued.

At an event in St. Louis on January 31, 2025, Yarros shared that readers have more to discover about the isles Violet explores in "Onyx Storm." When host Lexi Ryan asked her why there was no map of the isles included in "Onyx Storm," Yarros said it "was deemed to be too spoilery" by her editorial team, suggesting Violet doesn't know all she will about the isles by the end of book three.

Speaking more on signet powers in Denver, Yarros said readers had only seen "like 10%" of Violet's dream-walking abilities, in part because others who developed the power would have been killed, making it difficult for Violet to learn how to use the signet.

"There's probably one person alive that can train her," Yarros said, though she gave no information about who that person is.

She also said Xaden's "inntinnsic" signet has only reached "like 50%" of its potential, so his mind-reading abilities will likely grow in book four.

And Yarros revealed at the Los Angeles Festival of Books in April 2025 that she has a title picked out for the fourth book, though she didn't say what it was.

Yarros offered more information about the next 'Empyrean' novel in late 2025

When Yarros appeared at Romantasy Bookcon in Orlando in October 2025, hosted by Fabled Fantasy Events, she spoke with the hosts of the "Fantasy Fangirls" podcast, Lexi Ayala and Nicole Holleman, about the "Empyrean" series.

First, Yarros discussed how the dramatic ending of "Onyx Storm" will impact the next book, telling Ayala and Holleman that readers will know what happened to Violet during her 12 missing hours by the novel's end.

Yarros also warned that readers "should really be prepared in book four to see Xaden enter his villain era," indicating his marriage to Violet won't stop him from going full venin in the next "Empyrean" novel.

The "Fantasy Fangirls" also asked Yarros if Imogen had been wiping Violet's memories at other times in the "Empyrean" series, which many readers had been wondering after the ending of "Onyx Storm." Rather than giving a direct answer, Yarros said, "I think it depends on what you believe of Imogen's character. What has Imogen shown you of her character? What has she told Violet about her signet?"

In the "Empyrean" series, readers only see Imogen wipe memories when Violet or Xaden specifically ask her to. However, since the series is largely told from Violet's limited perspective, there may have been occasions when Imogen wiped people's memories without Violet's knowledge. The inclusion of multiple POVs in book four could offer new insight.

Likewise, Yarros addressed some of her readers' concerns surrounding Bodhi, as there is a contingent of "Empyrean" fans who think Xaden's cousin has feelings for Violet, saying, "Bodhi has a thing for what Xaden has. But he doesn't want to."

Her response indicates that Bodhi may be jealous of Xaden rather than in love with Violet. And considering he is one of the potential candidates to have turned venin at the end of "Onyx Storm," Yarros' response is particularly eyebrow-raising.

Finally, Yarros told readers to pay attention to the black dragons in the "Empyrean" series, encouraging them to ask themselves why there are so few black dragons in the world, adding that it's "very relevant" that two new baby black dragons hatched in "Iron Flame."

Hopefully, Yarros' clues can tide readers over until book four is published. In the meantime, they can read other romantasy novels to make the wait a bit more bearable.

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