The Scions have news to share following their foray into Castrum Meridianum.
This quest is available if you have completed the quest As It Once Was.
Starting the Quest
Talk to Alphinaud in the Rising Stones in Revenant's Toll in Mor Dhona to begin the quest.
Rendezvous with Krile
Go to Idyllshire and go southwest to the quest icon on the map and talk to Krile to proceed. There will be a cutscene.
Speak with Matoya
You can use the main Idyllshire Aetheryte to go to the Western Hinterlands via the Prologue Gate, or you can go southeast through the archway and use the southwest exit. Then go south to where the orange arrow is pointing in the minimap and check on the Cave Entrance to enter Matoya's Cave. Go south to where the quest icon is pointing in the minimap. Talk to Matoya and 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 (Main Scenario 1 > Dragonsong Main Scenario Quests > The Word of the Mother > Cutscenes 2 and 3.)
Use the Duty Finder or Duty Support to enter The Antitower. Please see the The Antitower Guide for a walkthrough.
After you complete the duty in The Antitower and exit the area, 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 Alphinaud
Talk to Alphinaud to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Alphinaud to accept the next quest: This War of Ours.