This page explains how to complete the level 80 post-Shadowbringers quest "Old Enemies, New Threats".
This quest is available if you have completed the quest Vows of Virtue, Deeds of Cruelty.
Starting the Quest
Talk to Krile in the Rising Stones in Mor Dhona to begin the quest. There will be a cutscene.
Speak with Maxima
Teleport to the Ala Mhigan Quarter in the Lochs and go northeast to where the orange arrow is pointing in the minimap. Talk to Maxima to proceed. There will be a cutscene.
Speak with Krile
Talk to Krile to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Krile to accept the next quest: The Way Home.