Eldest

Eldest a 668 page book by Christopher Paolini is about when Ergon goes to the Elves to complete his training to become a rider when his home village comes to siege because the Empire is looking for his brother for information.  When the Razaak {evil creatures of darkness} come to Rorans{Eragons brother} village, he decides its time to leave.  He arrives at the Varden just in time for a battle where Eragon is fighting another rider and just manages to escape with his life.