I think the book Brisingr is suitable for people who like reading about dragons and mythical beings, like elves, dragon riders, and magic. But If you are going to read this book I advise you to read the other part of the series first because I did not understand half of the book. So this is what I understood from it: they rescued a girl named Katrina. Eragon married his cousin Roran to Katrina. Let someone possess him to make him a sword for him to use then he named his sword that he made Brisingr which in their ancient language is fire.
Eragon and Roran were spying on a castle together so they could rescue Katrina from a guy named Galbatorix so they could get Katrina out of the castle and leave. Eragon stayed behind to rescue a prisoner that was left behind after rescuing Katrina from the castle. Then Eragon had to run to the Elvin woods across a desert. On the way to the Elvin woods, he found a friend and they traveled together till they got to the forest. They ran into some guards while running into the forest and almost got caught.
Then after going to the elven forest Eragon went to a lady blacksmith who swore never to forge another blade with her own hands. So she asked Eragon if she could use his body to forge the blade he was reluctant but let her use him. When the forging was done he passed out for the rest of the night then he woke up. His blade was almost done while he was asleep she had made a leather hilt and it just needed a name, he decided to name it Brisingr.
When he went to a fight to help he said its name and it burst into flames so he said it again and the flames went out. So he used it to cut enchanted gate locks to pieces with a few chops and opened the gate so he could get people through it.