This page explains how to complete the level 87 Endwalker quest "Caging the Messenger".
Requirements
This quest is available if you have completed the quest Follow, Wander, Stumble, Listen.
Starting the Quest
Talk to Hythlodaeus in Elpis to begin the quest.
Speak with Venat
Go northwest to where the orange arrow is pointing in the minimap. Talk to Venat to proceed. There will be a cutscene.
Special Characters in Duty Support
Ktisis Hyperboreia can be completed with special characters if you use the Duty Support system.
Ktisis Hyperboreia
Use the Duty Finder or Duty Support to enter Ktisis Hyperboreia. Please see the Ktisis Hyperboreia Guide for a walkthrough.
After you complete the duty in Ktisis Hyperboreia 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 Venat Again
Talk to Venat to complete the quest.
Unlock Flying in Elpis
"Caging the Messenger" is the final quest for unlocking Aether Currents in Elpis. If you have completed the other Aether Current quests and attuned to the Aether Currents in the field in this area (which you can find using the Aether Compass in Main Menu > Duty > Collection in this area) you will be able to fly in Elpis.
Next Main Scenario Quest
After you complete the quest, talk to Venat to accept the next quest: Thou Must Live, Die, and Know.