The third book in the Inheritance Cycle. The inpronouncable name means "fire", which is associated with the first spell that Eragon learns. However most readers have attributed it to the feeling of their brains being lit on fire due to the mind-boggling complexities of prose.
“Nasuada hoped he would soon recover. If he did not, she would ask Eragon or Angela, or perhaps the two of them together, to attend to Garven. Until such time as his condition improved, she decided that he should no longer serve as an active member of the Nighthawks; Jormundur would give him something simple to do, so she would not suffer guilt at causing his any further injury, and he might at least have the pleasure of enjoying whatever visions his contact with the elves had left him with.Bitter at her loss, and furious with herself, with the elves, and with Galbatorix and the Empire for making such a sacrifice necessary, she had difficulty maintaining a soft tongue and good manners.” Quote from Brisingr
by LockBreaker October 23, 2008