Solution

On the right path, take the right lift after the first boss. Kill the drakes in the second pack from largest to smallest. Loot the incense from the hidden room. Instead of opening the final boss's coffin, have one person /bow /respect /vpose /kneel before it, then defeat the secret boss.

Description

Deep beneath Ul'dah, beyond the twisting tunnels of the Sil'dihn aqueducts, we have discovered a vault in which slumbers a precious legacy. In its center, a catalog of evidence emblazoned with the words: “For coin, country, and comrades-in-arms, we bequeath this trust to the House of Ul.”

This solemn declaration, signed by the last sultan of Thorne, was followed by several pages of florid signatures─a procession of Ul'dahn rulers which ends with the name of my own father. And wedged there, betwixt one page and the next, a faded missive penned in his distinctive hand.

Addressed with the hope that the reader be “our darling Nanamo,” the letter describes the purpose of the vault. 'Tis a place known only to the royal heirs; a secure archive wherein evidence of Ul'dah's alliance with the Amalj'aa is preserved. And though tradition dictated this trust be passed on by word of mouth, Father felt that, should worse come to worst, 'twas safer to have an explanation committed to parchment.

“Dearest Nanamo, we wonder what manner of woman you have become. We know the role of sultana will challenge you in myriad ways, but no matter how your rule unfolds, remember that you shall ever be our greatest achievement. Seize what happiness you may each day, for joy is worth more than all the gil in Ul'dah.”

Mother. Father. Be assured that 'tis not sorrow which causes these tears to fall, but overwhelming pride. Now, in this moment, I am simply happy to be your daughter.