The Empyrean in Order (Fourth Wing and After)

Three books exist. A fourth main-arc novel is being written and has neither a title nor a date. A separate volume with a title and a date is not book four, which is where most of the muddle on the internet comes from.

The Empyrean books in order

1. Fourth Wing (2023) — Violet Sorrengail, built for the Scribe Quadrant and forced into the Riders Quadrant instead, in a school where the entrance exam is a bridge people fall off. Enemies-to-lovers with an unusually high body count.
2. Iron Flame (2023) — The consequences, a new commandant, and a much harder book — more interrogation, more politics, and a slower first half that divides readers.
3. Onyx Storm (2025) — The map opens outward: a quest structure, new territories, and answers to questions the first two books were careful not to resolve.

That is everything published. The series is planned as five books.

What Threshing Day is — and is not

Threshing Day is a companion volume of thirteen character and dragon stories, scheduled for late September 2026. It is not the fourth main-arc novel, it does not continue the story from Onyx Storm, and any reading order that slots it in as book four is wrong.

The actual fourth novel is unwritten as far as the public record goes — Yarros has confirmed she is working on it, with no title and no date announced. Anyone quoting you a release date for it is guessing.

It is worth being precise about this because the series is enormously popular and the rumour mill runs hot. Announcements, cover reveals and special editions circulate constantly, and a companion volume with a firm date is easily mistaken for the next chapter of the story. Nothing published or announced so far continues from where Onyx Storm stops.

Does the order matter?

Completely. This is a single continuous story with cliffhangers, not a set of connected standalones. Iron Flame begins days after Fourth Wing ends and assumes total recall; Onyx Storm does the same again. There is no entry point other than book one.

It is also worth knowing before you start that each book ends on a genuine cliffhanger. If waiting is intolerable, the series is currently a three-book wait with no announced end date — some readers deliberately pause until book four is dated.

The books also get considerably longer as they go. Fourth Wing is a brisk read built around a training year with clear milestones; Iron Flame is heavier on politics and interrogation, and Onyx Storm swaps the school structure for a travelling quest. If the first book sold you specifically on the war-college setting, know that the series leaves it behind.

If you are waiting for book four

The usual recommendations for the gap are ACOTAR for the romance, Throne of Glass for the training-and-war structure, and Powerless for the trials premise. All three are further along than The Empyrean and two of them are finished.