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

Rebecca Yarros is working on the fourth "Empyrean" novel. Casey Paul/MLB Photos via Getty Images 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 later told Elle that 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-Danlos syndrome, a connective tissue disorder, and POTS, 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. Rebecca Yarros. Rebecca Yarros/Red Tower Books 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. "Onyx Storm" by Rebecca Yarros. Red Tower 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