Over ten thousand years ago, a betrayal by the maddened black Dragon Aspect, Deathwing, shattered the strength and unity of the dragonflights. His most recent assault on Azeroth—the Cataclysm—has left the world in turmoil. At the Maelstrom, the center of Azeroth's instability, former Horde warchief Thrall and other accomplished shaman struggle to keep the world from tearing apart in the wake of Deathwing's attack. Yet a battle also rages within Thrall regarding his new life in the shamanic Earthen Ring, hampering his normally unparalleled abilities.

Unable to focus on his duties, Thrall undertakes a seemingly menial task from an unexpected source: the mysterious green Dragon Aspect, Ysera. This humble endeavor soon becomes a journey spanning the lands of Azeroth and the timeways of history itself, bringing Thrall into contact with ancient dragonflights. Divided by conflict and mistrust, these dragons have become easy prey to a horrific new weapon unleashed by Deathwing's servants . . . a living nightmare engineered to exterminate Azeroth's winged guardians.

Of even greater concern is a bleak and terrifying possible future glimpsed by Ysera: the Hour of Twilight. Before this apocalyptic vision comes to pass, Thrall must purge his own doubts in order to discover his purpose in the world and aid Azeroth's dragonflights as they face the Twilight of the Aspects.