You and Alphinaud and Arenvald will seek out Lyse to tell her the good news about what you have found.
This quest is available if you have completed the quest The Mad King's Trove.
Starting the Quest
Talk to Arenvald in The Lochs to begin the quest.
Speak with Lyse
Go to the quest icon on the map and talk to Lyse. There will be a cutscene.
Speak with Lyse Again
Talk to Lyse to proceed. There will be a cutscene.
Speak with the Prison Guard
Talk to the Prison Guard and say Yes to complete the quest. There will be a cutscene. This one is important, so it is recommended to watch it either now or via the Unending Journey in an inn room.
Next Main Scenario Quest
After you complete the quest, talk to Lyse to accept the next quest: Echoes of an Echo.