What is the main conflict in Enna Burning by Shannon Hale?

After her brother is consumed by fire due to using the gift, Enna also learns fire-speaking, promising herself not to misuse it and suffer her brother's fate. The novel's main conflict revolves around Enna's country needing her to help to win the war, and the fact that she begins to lose herself to the fire and must struggle against the element to prevent it from consuming her as well.