Fari-Wari is a little Tarutaru bard who's looking for inspiration for his latest masterpiece, and so he recruits the player, a hapless adventurer, to unearth the stories of the five Serpent Generals of Aht Urghan. This video shows the highlights, including the all important scene where Mihli Aliapoh makes her escape by jumping on the flat of the Elvaan general's blade, and then uses his face as a spring board to leap on to architecture. Well played, Ms. Aliapoh.
I think that quest line plus Three Men and a Closet (a.k.a. a good-natured parody of slashy subtext and yaoi fangirls) are probably my favorite quest stories in FFXI.