This page explains how to complete the level 90 post-Endwalker quest "Bridging the Rift".
This quest is available if you have completed the quest Sharing the Wealth.
Starting the Quest
Talk to the Veteran Radiant in Radz-at-Han to begin the quest. There will be a cutscene.
Speak with Y'shtola
Go to the nearest Aethernet Shard and use it to go to the Radz-at-Han Aetheryte Plaza. Go northeast to where the orange arrow is pointing in the minimap and talk to Y'shtola to proceed. There will be a cutscene.
Speak with Y'shtola at Sharlayan's Aetheryte Plaza
Teleport to Old Sharlayan and go to the quest icon, and talk to Y'shtola to proceed.
Speak with Montichaigne
Use the Aetheryte to go to the Studium. You can optionally enter the glowing circle in front of the building and talk to Y'shtola. Then enter the building and go northeast to enter the hallway, then go northwest to the end of the hallway, then go northeast into the room at the end. Go to the quest icon and talk to Montichaigne to proceed. There will be a cutscene.
Speak with the House Leveilleur Butler
Go southwest into the hallway, then go south to the main hall, then go southeast to exit the building. Use the Aethernet Shard to go to the Leveilleur Estate. Go to the quest icon and talk to the House Leveilleur Butler to proceed. There will be a cutscene.
Accompany Y'shtola to the Baldesion Annex
Go to the Aethernet Shard and use it to go to the Baldesion Annex. Enter the building and stand in the glowing circle, then talk to Y'shtola to proceed. There will be a cutscene.
Speak with Y'shtola Again
Talk to Y'shtola to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Montichaigne to accept the next quest: Restricted Reading.