After a brutal attack by the Hollowborn, Avril Williams has disappeared, and a severely injured Red Agent, along with Keres and Skye, must journey to a ravaged temple in eastern Europe in a desperate attempt to find her before its too late. Along the way, they discover a dark truth about their new foes that leaves them questioning everything

Meanwhile, Mystere and Kalen Vale are sent on a mission to help a victimized populace, only to realize that the Hollowborn arent the only deadly monsters hunting them