Onyx Storm will arrive in January 2025, and the next Fourth Wing sequel is poised to significantly raise the stakes of Rebecca Yarros’ story. That’s saying a lot, as The Empyrean Series is already action-packed and intense as-is. After Iron Flame‘s twist ending, however, things are bound to get darker for Violet Sorrengail and Xaden Riorson. And with the war against the venin now in full swing, Onyx Storm will likely feature more shocking reveals and heartbreaking casualties.