Scorched Wings by Frost Kay

Dahlia Skysinger has made the ultimate mistake: she assassinated the one man who could have freed her from the cruel grasp of the human royals—her husband. Now branded a traitor by both realms and haunted by the ghost of a love she never meant to destroy, Dahlia must outrun her hunters and the truth that could unravel two kingdoms.
To protect her family, she’ll make one final, desperate bargain. Even if it means surrendering her freedom once more.
King Neve has every reason to hate the woman who nearly cost him his life and crown. With his kingdom on the verge of civil war and vengeance burning through his veins, he should want her dead. But when fate entwines their paths once again, desire clashes with duty, and revenge becomes something dangerously close to redemption, he must make a choice that could destroy everything.

What happens when an imposter dares to tell the truth and a king finally lays down his sword? The cost may be their kingdoms… or their hearts.