After you tend to the enthralled in Eulmore, you look for a way to reach the top of the cliff in Kholusia.
This quest is available if you have completed the quest Paradise Fallen, and have reached level 78.
Starting the Quest
Talk to Alphinaud in Eulmore to begin the quest.
Speak with Urianger in Bottom Rung
You can either teleport to Wright or you can use the Eulmore Aetheryte to go to the Path to Glory (Kholusia) and go northwest to where the orange arrow is pointing in the minimap. Go to the quest icon and talk to Urianger to proceed.
Speak with Irvithe
Go south to where the orange arrow is pointing in the minimap. Talk to Irvithe to proceed.
Take Stock of the Lumber
Go to the southeast part of the orange circle on the map and check on the sparkling Lumber Stack.
Go to the south part of the orange circle on the map and talk to Grithil. There will be a cutscene.
Go north and go up the stairs, then go to the north edge of the orange circle on the map and check on the sparkling Lumber Stack.
Speak with Irvithe Again
Go to the stairs and go south down them, then go to the quest icon on the map. You can review the notes in the Key Items section of your inventory to count the lumber (hover over each note with the mouse or press the BACK button or SHARE button on controller to review the item information). When you are ready, talk to Irvithe. The correct answer is
Speak with Urianger
Go north to where the orange arrow is pointing in the minimap. Talk to Urianger to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Urianger to accept the next quest: The View from Above.