With a friend missing, Gavin must make a dangerous choice. Gavin struggles to understand the danger found on the other side of the realm. With Anna missing, he must find answers before the Forerunners destroy everything in his land. They must bring the attack into the other realm. But doing so exposes Alana, who Gavin has vowed to protect. The only way to truly help her is to understand her powers—and the new one Gavin possess. New powers mean new dangers, but may be key to stopping the Forerunners for good.