With the southern border breached, Aurora finds herself a land fighting a battle on two fronts. The dragons, riders, and Sound team face the dilemma of confronting the desolator to try and retrieve the lost Relic, or standing to fight the oncoming army. With the combined forces of the Sauderons and Rhoams, defenses begin to crumble, and the lands scorched by fire. But it is the land of their new enemy that harbors the final Relic. Betting the fate of their lives and their homeland, Ehlrist and his team gamble on seeking the final Relic in hopes that combined they will prove a powerful enough weapon to turn the tides of a losing battle. The search for the final Relic takes Ehlrist and his band of friends to this faraway land across the waters of the ocean, where lava and darkness await them. And through this search they learn a haunting that the Relics may have been nothing more than a sideshow to the enemy’s true end game. It may take the reconciliation and alliance of nations if their world is to have a chance at survival. But between failure and the final Relic lies a valley of darkness, and it is in this darkness that Ehlrist must learn to control the blackness running in his veins, or risk succumbing to it permanently
Koda and the other riders are forced once more to part with Ehlrist and Slate to protect their home and hope that they can keep the enemy at bay until he returns. They stand without the support of Relics against the greatest threat their lands have ever known. Koda must learn her place in the world as the other riders turn to her and the great white dragon in a time where all leadership has been lost in their ranks.
As the hunt for the final Relic continues, it becomes clear that the threat from Rhoam is not what it seems. The dragons, riders, and Sound team find themselves allying with Rhoams, rickers, and Sauderon himself to keep ahead of the enemy. But how far are they willing to go to make the ends justify the means? And will even the compromise of their convictions and faith be enough to buy back what has been lost?