The Firewalker once had a piece of armor that imbued her with the power and swiftness of flame. This artifact, more powerful than anything wielded by her allies and enemies alike, gave a mythical drive to her cause. The Fourth Warrior, as she was known to her companions, may have been killed, but her legend would be harder to destroy.
You must have the book, Snuffing the Fireknight (awarded from the collection quest), in your inventory to continue this questline. If the book has already been placed in your house, no quests will not be offered. If you do not want to travel back to your home, speak with Juna to purchase another one.