Reviews pointed out the similarities between Eldest and other works such as The Lord of the Rings,[7] while praising the themes of the book, such as friendship and honor.

[10] Eldest begins three days after the events of the preceding novel, Eragon, in the dwarf city of Tronjheim, inside of a hollowed mountain named Farthen Dûr.

Farthen Dûr is in the southeastern part of Alagaësia, the fictional continent where The Inheritance Cycle takes place.

Eldest begins as Ajihad, the leader of the rebel Varden force, is ambushed and killed, while The Twins and Murtagh are assumed dead.

Ajihad's daughter Nasuada is elected to command the Varden, and decides to move them to Surda and oppose the Empire openly.

Eragon and Saphira decide to travel to the forest Du Weldenvarden to be trained as a Dragon Rider by the elves.

The dwarf king, Hrothgar, adopts Eragon to his clan and has his now foster brother, Orik, accompany him to the forest.

Eventually, in an ancient elven ceremony, the Agaetí Blödhren, Eragon is affected by powerful magic, turning him into an elf-human hybrid, and healing his back injury.

Torn between chasing after Katrina and staying behind to defend his home, Roran rallies almost the entirety of the village to travel to Surda and join the Varden.

Eragon is revealed to have botched the blessing with poor phrasing, accidentally forcing Elva to feel the pain of others.

The Varden are then joined by an army of Urgals, led by Nar Garzhvog, who seek an alliance with them after being freed of Durza's control.

After the dragon, named Thorn, had hatched for him, they were both forced into swearing loyalty by Galbatorix in the ancient language, binding them to his will.

Eldest received generally negative reviews, and was met with criticism similar to Eragon for its derivative nature.

[7] BookBrowse also criticized Eldest, but said, as School Library Journal noted, that nothing the reviewers can say will stop some children from reading the book.

"[11] The Boston Globe gave a negative review for Eldest, criticizing the very low points and for "drama that rises to a wet pop.

[9] Barnes & Noble gave a positive review for Eldest, in particular for its style, characters and themes such as friendship, forgiveness, responsibility, and honor.

[19] Paolini commented on the theme in Eldest of vegetarianism:[20] "One of my goals as an author is to explore various aspects of human nature.

It's my job, then, to attempt to understand why people act, even if it differs from my own point of view or practice, and to present those reasons to the best of my ability.

An Entertainment Weekly review was negative toward the story because it was slow-paced, while The Washington Post said Eldest needed to be shortened.

"On the other hand, Barnes & Noble called the writing style fluid[9] and Children's Literature praised the story for being richly detailed.

Kirkus Reviews compared the story to a patchwork of fantasy elements and characters, then concluded that it, despite being derivative, was exciting and held together well.