In basic terms, Brisingr is defined as “fire” in the ancient language. Readers may recognize that this word was the first spell ever to be uttered by Eragon. Brom taught him how to harness the natural power of spellcasting through this word. In Brisingr, after recognizing that author Christopher Paolini has chosen to use this word as the title for his third novel in the Inheritance series, the first instance where the word appears is when Eragon, Saphira, and Roran are attempting to find an entrance into Helgrind. By invoking a modification on the spell, Eragon produces a red werelight which they are able to use as a guide and defense mechanism on the mountain.

Eragon goes on to use the ancient spell several more times within the first chapters to demonstrate its usefulness both as a weapon and as a guide for the travelling party. The second time Eragon invokes Brisingr, using the spell produces a fireball that is capable of distracting the Ra’zac and Lethrblaka in combat in Helgrind. He goes on to use the spell a third time in order to create a light so that he and Roran can find Katrina in her cell.