An ancient enemy escapes his eternal exile behind the Eternal walls. A seer warns of a cruel sacrifice Luna must make. And the Shield of Time disappears into hands that would use it to destroy reality.

At least, Luna has finished her semester.

Caught between the secrets of the Shadow Master and the allure of the mythic King of Kings, confused by her unresolved feelings for Winter, Luna must gear up for a busy summer break, trying to prevent Horror and an onslaught of power-hungry Immortals from destroying humanity and time as we know it.