Darkest Mercy is the 5th and final book of the Wicked Lovely Series by Melissa Marr.
Marr’s words: “This is . . . well, almost the final cover. The vines are still wrong, but the effects are in place now. I love it. Please, meet Donia (portrayed by Linda) on the cover of the final WICKED LOVELY book . . . LOVE the steam & sunlight.”