A Crown of Ruin by Jennifer L. Armentrout

When everything falls apart, the truth of who they are is revealed.

Poppy has fallen into stasis, her body broken and power spent, carried beyond the mortal realm. While she lies suspended in dreams, Casteel faces a world without her—raw, wrathful, and altered in ways he doesn’t yet understand.
Left to steady a kingdom trembling under the weight of loss, Kieran shoulders what he cannot say aloud, even as the fractures between gods, mortals, and fate widen around him.
In the days that follow, grief becomes a guide, loyalty a burden, and love the only thing holding the realms together.
These are the pieces that fill the silence. The moments of wrath, ruin, resolve, and the spark of what must come next.

A Crown of Ruin reveals the unseen moments of love, loss, and change that happened between The Primal of Blood and Bone and The Throne of Bone and Ash.