What is The Threshing Day book?

The Threshing Day is a September 29, 2026 companion volume in Rebecca Yarros' Empyrean series featuring 13 character-focused stories — not mainline Book 4.

What order should I read The Threshing Day?

Read Fourth Wing, Iron Flame, and Onyx Storm first. Then read The Threshing Day. Spoilers for Onyx Storm and earlier books apply throughout the companion.

Is The Threshing Day required for Dragonkind?

No. Dragonkind at dragonkind.com is playable without reading, but companion stories add emotional context to Empyrean interactive media launched October 1, 2026.

How does The Threshing Day connect to the Signet Quiz?

Both are official Empyrean touchpoints around the same marketing window. The Signet Quiz is at threshingday.com/quiz.html — separate from the book and Dragonkind.