Rebecca Yarros attends the PEN America 2026 Spring Literary Gala in May 2026. Joy Malone/Getty Images Rebecca Yarros announced that she is working on book four of the "Empyrean" series. The "Fourth Wing" author published book three, "Onyx Storm," in January 2025. The author has offered hints about how Violet Sorrengail's story will continue. Spoilers ahead. Rebecca Yarros' next "Fourth Wing" novel is finally on its way. It's been over a year since Yarros released "Onyx Storm," the third ins...