Series

Annabeth is terrified. Just when she's about to be reunited with Percy - after six months of being apart, thanks to Hera - it looks like Camp Jupiter is preparing for war. As Annabeth and her friends Jason, Piper, and Leo fly in on the Argo II, she can't blame the Roman demigods for thinking the ship is a Greek weapon.

She is the last of her kind...It is not a peaceful time in the Dells. In King City, the young King Nash is clinging to the throne, while rebel lords in the north and south build armies to unseat him. War is coming. And the mountains and forest are filled with spies and thieves.

In the center of Luster towers an enormous tree that is the Heart of the World. Now the tree is wounded, pierced by a tunnel that connects it to Earth. Through that tunnel strides Beloved, the ancient enemy of the unicorns, followed by an army of Hunters eager to destroy every last unicorn.

Luster, the world where the unicorns fled to escape the Hunters who have sworn to wipe them out, has dangers of its own - as Cara discovers when she attempts to cross that world in a desperate effort to rescue her grandmother.