Published October 2, 2026
Is Threshing Day Empyrean Book 4?
Clear answer: Threshing Day is a companion collection, not the next main novel after Onyx Storm.
No. Threshing Day is not Empyrean Book Four.
It is a companion collection of thirteen short stories set on Threshing Day at Basgiath War College. It does not continue the central plot of Violet Sorrengail and Xaden Riorson after Onyx Storm. The publisher and author have stated this explicitly in the official materials.
The main series reading order remains:
- Fourth Wing
- Iron Flame
- Onyx Storm
- (future Book Four – title and date not yet announced in the sources used here)
Threshing Day can be read after Onyx Storm for deeper background on how specific riders first bonded with their dragons. It is not required for understanding the next main novel when that title is released.
Source: official publisher descriptions on threshingday.com and the Entangled product page.