This page explains how to complete the Endwalker Main Scenario Quest "The Jewel of Thavnair".
This quest is available if you have completed the quest In the Dark of the Tower.
Starting the Quest
Talk to Thancred in Thavnair to begin the quest.
Optional: Thavnair Aether Current
You can optionally go southeast and then northwest to find a nearby Aether Current. You can use the Aether Compass (found in Main Menu > Duty > Collection) to help you pinpoint its location. Check on the Aether Current to attune to it.
Speak with the Radiant Guardsman
Go southeast (if you didn't get the Aether Current), then go east to where the orange arrow is pointing in the minimap. Talk to the Radiant Guardsman to proceed.
Speak with Estinien
Talk to Estinien and he will accompany you.
Speak with the Attentive Radiant
Go northwest to where the orange arrow is pointing in the minimap. Attune to the Aethernet Shard, then go to the quest icon and talk to the Attentive Radiant.
Speak with the Watchful Radiant
Go up either set of stairs next to the fountain, then go southwest up the stairs. At the top, go northwest up the stairs and through the large door there. Speak to the Watchful Radiant to proceed.
Speak with the Vigilant Radiant
Go southwest up the stairs and through the door at the top. Attune to the nearby Aethernet Shard, then talk to the Vigilant Radiant to proceed.
Speak with the Meghaduta Attendant
Go northwest up the stairs and continue northwest to where the orange arrow is pointing in the minimap. Attune to the Aethernet Shard, then go up the stairs to the quest icon on the map. Talk to the Meghaduta Attendant to proceed. There will be a cutscene.
Speak with Alisaie
Go to the quest icon on the map and talk to Alisaie to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Alphinaud to accept the next quest: The Color of Joy.