Rebecca Yarros' bestselling fantasy book 'Fourth Wing' is being turned into a TV show. Here's everything we know so far.

• Rebecca Yarros' "Fourth Wing" is being adapted into a TV series.
• Amazon MGM Studios and Michael B. Jordan's Outlier Society will produce the series for Prime Video.
• Although a release date and cast hasn't been announced, Yarros offered some clues about the show.

Rebecca Yarros' "Empyrean" series about dragon rider Violet Sorrengail has never been more popular.

When "Onyx Storm," the third book in the romantasy series, was released on January 21, it became the fastest-selling adult novel in 20 years, The New York Times reported.

The first and second books in the series, "Fourth Wing" and "Iron Flame," sat right behind "Onyx Storm" on the bestseller list following its release.

Yarros is taking a break before writing the fourth book in the series, but in the meantime, progress is being made on the series adaptation of "Fourth Wing."

Here's everything we know about the show so far.

'Fourth Wing' is becoming a TV show

In October 2023, Deadline announced that Amazon MGM Studios and Michael B. Jordan's Outlier Society were developing "Fourth Wing" into a Prime Video series. Yarros is also an executive producer for the show.

Outlier Society produced Jordan's "Creed III" and is developing a slate of other series and films in addition to "Fourth Wing."

In July 2024, Outlier Society announced it had hired Moira Walley-Beckett as the showrunner for the series. Walley-Beckett won three Emmy awards for her work as a writer and producer on "Breaking Bad," and she later created "Anne with an E."

As of February, Outlier Society had not announced casting or a release date for the series.

Deadline also reported in October 2023 that Amazon MGM Studios had bought the rights for the whole "Empyrean" book series. In a January interview with Variety, Yarros said she had shared the "five-book arc" for the "Empyrean" series with Amazon and Walley-Beckett.

"They have the five-book arc and the general big points of what happens in between each book, but they don't have the specifics between Book 4 and Book 5, because I'm getting ready to go to my crazy plotting board and plot out every single event that happens in each book so that I make sure that I'm within my two books there," she told Variety.

Yarros talked about the series' pilot while on a book tour for 'Onyx Storm'

Although details about the series are limited, Yarros made a few comments about the show while promoting "Onyx Storm."

Speaking at an engagement on January 24 in New York, Yarros told fans she had read the pilot for the "Fourth Wing" show — and loved it.

"I read the latest version of the pilot last week," she said. "It's really nerve-racking when you read something like that because you're really — you're trusting someone else with your baby, right? And you're trusting someone else to say, like, 'Hey, this is important in your work, and this isn't,' and you kinda get your guard up."

"But guys, I, like, kicked my feet the whole time," she said. "You're gonna love it."

Yarros also praised Walley-Beckett, calling her a "brilliant writer" and saying she maintained the integrity of the book in the pilot.

"All the lines that you love are there. And she really kept the spirit and energy," Yarros said of the pilot. "I can't say enough good things. It's phenomenal."

Yarros has shared some thoughts on casting

Speaking at an event in London on August 30, 2024, Yarros said casting will ultimately fall on the show's staff, not her. She also said she intentionally hasn't shared any specific actors she hopes will be cast in the series.

"I will never say who my perfect fan cast is because the cast is so diverse, and I want to open that up to more diversity," she said. "And I feel like the second I say who I think this character is, that's who everyone will accept. That's only who they will accept."

"I kinda hope they find, like, an up-and-coming generation," she added. "But I would never put my fan cast in your heads."

Although she won't be involved in casting the series, Yarros said at the same event that she has one hard-line casting request she has communicated to Amazon MGM Studios, Outlier Society, and Walley-Beckett.

"They know how staunch I am against white-washing Xaden," she said. "I think that's the biggest thing."

Xaden Riorson, Violet's love interest in the series, is described as having "warm tawny skin" in "Fourth Wing" and "tawny-brown" skin in both "Iron Flame" and "Onyx Storm."