A Dark Eternity (Whims of Fae Volume 4)

Now ruler of the Sidhe, Scarlett must learn how to be the queen her people need.Since absorbing the power of The Life Tree, everything has changed. Scarlett is queen of a realm, until a few weeks ago, she didn't even know existed and has more magic than she ever thought possible. But she worries it still isn't enough to protect those she cares about or to find a way to bring Raith, who had sacrificed himself to save his mother, back. With a looming war against a new enemy no one knows much about, Scarlett and Kaelem must find as many allies as they can. When a magical book teaches Scarlett dark magic, she must decide how much of herself she will risk becoming the leader everyone needs her to be.