Brisingr, The Inheritance Cycle: Book Three/Christopher Paolini

Oaths sworn...Loyalties tested...Forces collide. Eragon and his dragon, Saphira, have narrowly escaped with their lives after the colossal battle against the Empire's warriors on the Burning Plains. Now Eragon finds himself bound by promises he may not be able to keep. He must help rescue his cousin Roran's beloved from King Galbatorix's clutches. But he also owes his loyalty to the Varden, the elves and the dwarves, who are in desperate need of his talents and strength. Eragon in the greatest hope to rid the land of tyranny. Can this once simple farm boy unite the rebel forces and defeat the king?