Threshing is the day every first-year cadet at Basgiath War College finds out whether a dragon will bond with them. Most walk out of the valley with one, or without one. A few do not walk out at all. This collection gathers thirteen cadets' own versions of that day, across the world of Fourth Wing and Iron Flame.
One of the thirteen belongs to Xaden Riorson. His bond with his dragon, Sgaeyl, has so far only been shown through Violet Sorrengail's eyes. The rest follow other cadets and riders through the same field, each with a different stake in the outcome.
Each story is illustrated: the first edition includes sixteen full-color pieces by artist Joe Requeza. Yarros has described the book as a companion to the Empyrean series, set apart from its fourth novel, filling in a day the earlier books only referenced in passing.
It carries the same violence as the main series. Cadets die at Basgiath, and Threshing is where many of them do. Readers already invested in Fourth Wing and Iron Flame will get the most from it. It is not the place to start the series.