With the way open to Golbez's lair, you are ready to fight the voidsent within.
This quest is available if you have completed the quest Back to Action.
Starting the Quest
Talk to Varshahn on the Red Moon to begin the quest. You can reach the Red Moon from Mare Lamentorum. There will be a cutscene.
The Lunar Subterrane
Use the Duty Finder or Duty Support to enter the Lunar Subterrane. Please see The Lunar Subterrane Guide for a walkthrough.
After you complete the duty in the Lunar Subterrane and exit the area, there will be a cutscene.
Speak with Zero
Talk to Zero to proceed. If you are ready, say Yes. There will be a cutscene.
The Abyssal Fracture
Use the Duty Finder to enter The Abyssal Fracture. Please see The Abyssal Fracture Guide for a walkthrough.
After you complete the duty in The Abyssal Fracture and exit the area, there will be a cutscene.
Speak with Zero Again
Talk to Zero to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Vrtra to accept the next quest: Reunited at Last. There will be a cutscene.