Dragon Quest - The Stone Crown Series, #2

She can save her people-or doom the world. Narissea faces an impossible choice. Armed with a map discovered in the hidden shrine, she's forced to lead Inyene's heir through the wilds of the Plains to claim the ultimate prize. For only the wearer of the Stone Crown can command all dragons, and take the High Throne that rules over the three kingdoms. To place the crown's power into Inyene's hands is unthinkable.
Yet failure to obtain it means certain death. But the small band is not alone. Vicious mercenaries seek the crown for their mysterious patron and attack Narissea's expedition when they least expect it. In the ensuing chaos, the map is torn in two, forcing Narissea to rely on her memories of landmarks and stories passed down by the village elders to make her way through the Plains and its treacherous Sea of Mists.
When Inyene suspects betrayal, she sends her mechanical dragons against the beleaguered band, and the sands erupt in an epic clash of forces. Narissea's desperate decisions threaten to alter destinies, but she'll do whatever it takes to save her people. No matter the consequences.