Tempered: Dragons' Trust Book 4 (Volume 5)

Renick, Thane, and Lainey must face down the original enemy of the Dragon Kind. The centuries-old man who slaughtered dragons and stole their heart stones to feed his own greed for power. Individually they lack the strength to vanquish the greatest foe they have ever faced. Together and with the added strength of old and new allies, they might just succeed. But when they think they have the Autarch trapped, he proves more powerful than the ever imagined. If they do not find a way to defeat him, their fate, and the fate of those that stand with them will be sealed.