With Seiryu's Wall ready to deploy, Hien is free to dispatch reinforcements to Ala Mhigo, where you will go to attempt a parley.
This quest is available if you have completed the quest Seiryu's Wall.
Starting the Quest
Talk to Hien in the Kienkan in the Doman Enclave to begin the quest.
Speak with the Resistance Fighter in Porta Praetoria
Teleport to Porta Praetoria in The Lochs and go east to where the orange arrow is pointing in the minimap. Talk to the Resistance Fighter and say Yes to go to Alliance Headquarters. There will be a cutscene.
Speak with Lyse
Talk to Lyse and say Yes if you are ready to proceed. There will be a cutscene.
Speak with Alisaie
Talk to Alisaie to proceed.
Speak with the Alliance Leaders
Talk to Merlwyb, Hien, and Nanamo.
Report to Alisaie Again
Talk to Alisaie to proceed. There will be a cutscene.
Speak with Lyse Again
Talk to Lyse to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Lyse to accept the next quest: The Face of War. There will be a cutscene.