This page explains how to complete the level 80 post-Shadowbringers quest "A Notable Absence".
This quest is available if you have completed the quest Nowhere to Turn.
Starting the Quest
Talk to Alphinaud in Eulmore to begin the quest.
Go to the orange circle near the Aetheryte on the map. Go to the west part of this orange circle and talk to Mowen to proceed.
Use the Aetheryte to go to the Glory Gate. Go through the door into Eulmore and go to the south part of the orange circle. Talk to Cornenne to proceed.
Go north to the Aethernet Shard and use it to go to the Southeast Derelicts. Go north to the orange circle on the map. Go just west of the center of the orange circle and talk to Hathenbet to proceed.
Speak with Alphinaud
Go south to the Aethernet Shard and use it to go to the Glory Gate. Go to the quest icon and talk to Alphinaud to hand over the notes and complete the quest.