Rebecca Yarros, who is known for the Empyrean series, which includes "Fourth Wing" and "Iron Flame," revealed the cover of "Onyx Storm," the third novel in the series.

The second book in Yarros' Empyrean series, titled “Iron Flame,” out Nov. 7, has its cover art, an illustration that twins with “Fourth Wing.” “Iron Flame” by Rebecca Yarros "Iron Flame" ...