While the Scions investigate a means to find another of the missing, you head to Limsa Lominsa to meet several returning Scions.
This quest is available if you have completed the quest As Goes Light, So Goes Darkness.
Starting the Quest
Talk to Tataru in Ishgard to begin the quest.
Rendezvous with F'lhaminn
Go to Limsa Lominsa and use the main Aetheryte or an Aethernet Shard to go to the Arcanists' Guild Aethernet Shard. Go to the quest icon on the map and talk to F'lhaminn. There will be a cutscene. This one is important, so it is recommended to watch it either now or via the Unending Journey in an inn room.
Speak with F'lhaminn in Revenant's Toll
Go to Revenant's Toll in Mor Dhona. F'lhaminn is near the Aetheryte. Talk to her to proceed.
Speak with the Scions in the Rising Stones
Go through the nearby doors and enter the Rising Stones. Go to the quest icons on the map and talk to F'lhaminn, Aergmhus, Homei, Coultenet, and Hoary Boulder to proceed.
Speak with Tataru
Talk to Tataru to complete the quest. There will be a cutscene.
Next Main Scenario Quest
After you complete the quest, talk to Alphinaud to accept the next quest: The Word of the Mother.