Rebecca Yarros Dominates the Bestseller Charts With Threshing Day

Rebecca Yarros did not need a full-length fourth Empyrean novel to take over the bestseller chart. A 224-page companion collection was enough.

Threshing Day, released September 29 by Red Tower Books, sold 857,802 print copies in its first week, according to Circana BookScan data published by Publishers Weekly. That sent the book straight to No. 1 on PW's overall bestseller list and made it the biggest book debut of 2026 so far.

The scale of that number is even more striking when you look at what was behind it. John Grisham's The French Illusion, the No. 2 title on the same overall list, sold 68,697 copies during the measured week. Yarros was not simply first. She was operating in a completely different sales bracket.

🐉 What exactly is Threshing Day?

This is where the sales become particularly interesting. Threshing Day is not the long-awaited fourth main novel in the Empyrean series. It is a companion collection built around one of the most dangerous rites at Basgiath War College: the day first-year rider cadets attempt to bond with dragons.

The book contains thirteen stories following familiar characters through their own experiences of Threshing. The publisher's official description names Xaden Riorson, Rhiannon Matthias, Dain Aetos, Liam Mairi, Ridoc Gamlyn, Sawyer Henrick, Garrick Tavis, Imogen Cardulo, Bodhi Durran, Mira Sorrengail, Brennan Sorrengail, Aaric Graycastle and Sloane Mairi.

That structure gives Yarros something a normal sequel could not do as easily. Instead of moving the central plot forward through a single narrative, the collection circles back through characters readers already know and asks what happened to each of them at a moment that shaped the riders they would become.

📈 A companion book just outsold almost everything released this year

There is an obvious temptation to look at 857,802 copies and treat it as just another giant Rebecca Yarros number. That would miss the more interesting part.

Companion books usually serve the existing fandom. They fill gaps, offer alternate points of view, or give devoted readers extra time inside a world they already love. They are not always expected to behave like a major series installment.

Threshing Day did.

According to Publishers Weekly, its first week immediately made it the third-bestselling book of the entire year to date. The only titles ahead of it were Allen Levi's Theo of Golden and Andy Weir's Project Hail Mary, both of which accumulated their 2026 totals over a much longer period.

In other words, Yarros compressed months of normal bestseller momentum into a single launch week.

⚔️ Why readers were ready to go back to Basgiath

The Empyrean series has been unusually good at turning waiting into part of the experience. Fourth Wing introduced Basgiath, dragon riders and Violet Sorrengail in 2023. Iron Flame followed later that year, and Onyx Storm arrived in 2025. Each release produced another wave of theories, character debates and rereads.

But the next main novel still has no official publication date.

That puts Threshing Day in a useful position. It gives readers something genuinely new without forcing Yarros to rush the next central installment. At an October 1 launch event at One Times Square, Yarros explained that the companion was designed as a way for readers to step back into the series if they wanted to, while making sure it would not become mandatory homework.

She also said that anything readers truly need to understand the fourth main book will be worked into that novel. That is a small but smart promise. Expanded universes can become exhausting when readers feel they need every spin-off, special edition and side story simply to follow the main plot.

🎧 The success is not limited to print

The book's launch has also travelled well across formats.

On Apple Books' US rankings dated October 6, Threshing Day held the No. 1 position in both paid books and audiobooks. Audible's fiction bestseller list for the week ending October 2 also placed the audiobook at No. 1.

That matters because the modern blockbuster book is increasingly a multi-format event. A reader may buy a special hardcover for the shelf, listen to the audiobook on the way to work, or move between digital and print editions. The chart performance suggests the appetite for Yarros's world is not confined to one format or one kind of reader.

🗓️ From release day to chart takeover

🔮 What this means for Empyrean Book Four

The obvious next question is the one Yarros readers have been asking for months: when does Book Four arrive?

There still is not an official date.

Yarros confirmed at the New York launch that she is working on the next installment. Until the publisher or author announces a date, anything more specific should be treated as speculation.

But the commercial message from Threshing Day could hardly be clearer. Interest in Empyrean has not cooled during the wait. If anything, a book that deliberately steps sideways from the main narrative has demonstrated just how large the audience remains.

That makes the eventual fourth novel one of publishing's easiest future blockbusters to predict, even if its title and release date remain unknown.

For now, readers have thirteen smaller stories, one brutal day at Basgiath, and a sales figure that makes the word “companion” sound almost comically modest.

🔎 Sources used for this article