Alphinaud asks you to escort Yugiri to Revenant's Toll and introduce her to Minfilia and the guild representantives there.
This quest is available if you have completed the quest Why We Adventure.
Starting the Quest
Talk to Alphinaud in the Quicksand near the Adventurers' Guild aetheryte in Ul'dah to begin the quest.
Speak with Slafborn
Go to Revenant's Toll in Mor Dhona and talk to Slafborn near the Aetheryte. There will be a cutscene.
Speak with Yugiri
Speak with Yugiri to proceed.
Speak with Minfilia
Go south from the Aetheryte through the doors, and check on the Rising Stones Entrance, then go south to the Solar. Talk to Minfilia and there will be a cutscene.
Speak with Minfilia Again
Talk to Minfilia to complete the quest. There will be a cutscene.
Next Main Scenario Quest
After you complete the quest, talk to Minfilia to accept the next quest: The Sea Rises.