Emmanellain asks you to accompany him while he regales Laniaitte with the story of his heroic exploits.
This quest is available if you have completed the quest A Series of Unfortunate Events.
Starting the Quest
Talk to Emmanellain in the Sea of Clouds to begin the quest.
Speak with Laniaiatte
Go east and down the wooden stairs, then go southeast to where the orange arrow is pointing in the minimap. Talk to Laniaitte and there will be a cutscene.
Speak with Haurchefant in Ishgard
You can either go northwest to the wooden stairway and go up, then go west to the airship and talk to the Airship Attendant there to return to Ishgard, or you can just teleport there and go to the Athenaeum Astrologicum. Go to the quest icon and talk to Haurchefant to proceed.
Speak with Emmanellain in Fortemps Manor
Use an Aethernet Shard to go to the Last Vigil Aethernet Shard, and talk to the House Fortemps Guard to enter Fortemps Manor. Talk to Emmanellain to complete the quest. There will be a cutscene.