Eragon was just a 16 year old boy when a dragon egg found in the mountains changed his life forever. The egg hatched for him and made him become a dragon rider which is an immortal person that is capable of doing magic. They also have a dragon to help. He also is the first free rider in a century.
While looking for guidance he finds mysterious creatures called Ra'zac stalking his home. During this he finds his egg has hatched and that he has a mental connection to the dragon for communication. The dragon's name is Saphira. The Ra'zac, while Eragon was taking care of his dragon in the woods burned down his home with his uncle Garrow inside.
Eragon figures the Ra'zac did kill his uncle and burned his home down so he sets off with Saphira to chase the Ra'zac. The village storyteller Brom catches him and tells him he has experience with evil and trains Eragon in magic and swordplay.
During their quest for the Ra'zac, they lose the trail of them. They go to somewhere called Dras Leona which is the place of the end of the trail. They unfortunately run into the Ra'zac and get captured. A mysterious traveler named Murtagh saves them but Brom dies from injuries. Eragon and Murtagh continue after giving Brom a proper burial and get to Gilead. Eragon gets captured again by a Shade named Durza who is the right hand man of the evil king Galbatorix. They see an elf in Gilead who is deathly ill and in Eragon's dreams. Murtagh and Saphira save Eragon and the elf and they travel to Farthen Dur, a mountain where the Varden, an organization committed to kill Galbatorix is staying.
They reach Farthen Dur and give the elf, Arya treatment and get welcomed by the dwarves and humans. First, they had to get their minds checked by twin magicians named The Twins. Also a dwarf named Orik leads them around and they become friends. The leader of the Varden, Ajihad tells them Durza, Kull, and Urgals, monsters with horns and are 7 ft tall, are coming to attack Farthen Dur under the command of Galbatorix. They also learn that Murtagh is the son of a dead evil Dragon Rider and imprison him.
They defeat the Kull and Urgals and rejoice in victory. Eragon also defeats Durza with the help of Arya and Saphira but he sustains a sword injury on his back and the dwarves most prized gem is destroyed too. Shades are almost impossible to kill because you can only kill a shade if you stab it through the heart and there had only been 2 other people who had killed a Shade. The book is ended where Ajihad, Murtagh, (who proves himself on the battlefield), and The Twins disappear.