After the Sultana and her General personally invite you to the upcoming banquet, Owyne has some advice for you.
This quest is only available if you started the game in Ul'dah, and you have completed the quest Duty, Honor, Country.
Starting the Quest
To begin this quest, go to the Heart of the Sworn in Ul'dah (speak with the Sultansworn Elite near the Alchemists' Guild to enter) and talk to Owyne.
Speak with Momodi
Go to the Adventurers' Guild in Ul'dah and talk to Momodi in the Quicksand.
Collect the Earrings
Go to the Goldsmiths' Guild in Ul'dah and talk to Serendipity to get the wooden lockbox.
Deliver the Wooden Lockbox
Go back to Momodi at the Adventurers' Guild and talk to her. Hand over the rosewood box to complete the quest.
Next Main Scenario Quest
After completing the quest, talk to Momodi to accept the next quest: A Royal Reception.