As you and Minfilia depart for the banquet in Ul'dah, Riol reveals that Teledji Adeledji has been bribing some members of the Crystal Braves.
This quest is available if you have completed the following three quests:
Starting the Quest
Talk to Minfilia in the Rising Stones in Revenant's Toll in Mor Dhona to begin the quest.
Speak with Minfilia
Go to Ul'dah and go to the Chamber of Rule Aethernet Shard. Go south to the quest icon and talk to Minfilia to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Minfilia to accept the next quest: Come, but Not Gone.