Eragon is a simple farm boy, living in a village in a secluded corner of a country known as Alagaësia. So far, so tame.
One day, while out hunting, he hears an explosion in the woods. When he investigates, he finds a blue stone in the middle of the wreckage. Thinking he might sell it for some food (seeing as how it scared off all the deer—way to go, exploding rock), he takes it home.
Back at the farm, he tells his Uncle Garrow (who has raised him from childhood) and cousin Roran about what he found. When they can't sell the stone, Eragon ends up keeping it in his room. Then, late one night, the stone squeaks. Then it cracks. Then out pops a dragon. Well, then.
When he touches the dragon, Eragon is overcome with a charge of energy. He seems to have developed a mental link with it, and he's got a white scar on his palm to show for it.
Eragon ends up hiding the dragon in the woods, sneaking off to bond with it as the creature gets bigger and bigger. Over time, their bond develops and Eragon names this she-dragon Saphira. But trouble comes to town. Two shady characters show up asking about the stone, so Saphira grabs Eragon and they hightail it (literally—he flies on her back) out of town.
When they return, it's more bad news. Eragon's home has been destroyed and Uncle Garrow eventually dies from the wounds he suffered in the explosion. (Tissue break.) Eragon is majorly bummed out, to put it mildly, but he decides to take vengeance on his uncle's killers. Garrow was found with a scrap of black cloth in his hand, so Eragon's pretty sure those two shady fellas who showed up in town had something to do with his death.
As he leaves his village to start on his revenge trek, Eragon is waylaid by the town storyteller, Brom. He tells Eragon that the two baddies he's after are supernatural beings called the Ra'zac, who are working for the evil King Galbatorix. Killing them will be a pretty tall order, so Brom convinces Eragon that he needs his help. All three—Brom, Eragon, and Saphira—head off on the trail of the Ra'zac.
As they travel through Alagaësia, Brom starts to train Eragon in the ways of magic and swordplay. He explains that Eragon has inherited the mantle of the Dragon Riders, a group of heroes who have long since died out. He and Saphira are the first of their kind to come along in many years, and now they are wanted by Galbatorix and his Empire—either to join the forces of evil or… die.
Eragon trains and grows stronger, and eventually the three of them track the Ra'zac to a town called Dras-Leona. Unable to take their revenge, the three of them are instead chased from the town and poor old Brom is killed in the process. Saddened by yet another loss in his life, the hole left by Brom is filled with a new stranger named Murtagh, who agrees to help Eragon on his quest for his own reasons (which he won't tell Eragon…or us—boo!).
Things go well until Eragon is captured by a bunch of monsters, called Urgals, who work for the king. Eragon gets locked up, but Murtagh helps to break him out. In their escape, they also rescue an elf named Arya (natch), whom Eragon has seen in his dreams. Just one problem: she's unconscious. Meanwhile, Eragon is attacked by an evil magician or Shade named Durza. Not to worry: Murtagh shoots Durza in the face with an arrow (muahaha)… but we're not sure if he's really dead.
Are you exhausted from all the excitement? Too bad, there's more. After the escape, the group is chased all the way across the Hadarac Desert and into the gigantic Boer Mountains. There they find protection with a rebel group called the Varden, who are working with the elves and the dwarves to unseat the king and bring down the alliance. Sounds great, right? But—oops—turns out Eragon and Co. have led the Urgals right to the mountain hideout.
It's not all bad, though (for us, at least). It leads to a colossal battle, which the good guys win (gasp!) and in which Eragon manages to kill the Shade. (He does it the only way he can: tickling him to death. Oh wait, no, he stabs him in the heart.) While Eragon is laid up, recovering from the battle, he's visited mentally by the Cripple Who is Whole—yep—who invites Eragon to visit him (or her, unclear). Eragon agrees—because, you know, things have been simple for him up to this point—and the book ends with his resolution to make it happen.