Forgemaster H'naanza asks you to lend your assistance at the Moraby Drydocks.
This quest is only available if you started the game in Limsa Lominsa, and you have completed the quest Relighting the Torch.
Starting the Quest
To start the quest, talk to H'naanza in Limsa Lominsa, south of the Aftcastle aetheryte.
Deliver the Missive to Ahtbyrm
After accepting the quest, you need to go to Lower La Noscea. Fortunately, there is a gate to that area near H'naanza. It's to the east.
Once in Lower La Noscea, make your way east, then south. You will cross a bridge. As you continue going south, look to the left and you will see a gate. Go through it to enter the Moraby Drydocks.
Attune to the Aetheryte
After you pass through the second gate, go down the stairs in front of you, then go south to find the aetheryte. Be sure to attune to it.
Talk to Ahtbyrm
After attuning to the aetheryte, go north again, but this time go down a short flight of stairs to the right of a wagon. From there, go east up some stairs and you will find Ahtbyrm. Talk to him to deliver the missive. There will be a cutscene.
Next Main Scenario Quest
After completing the quest, you will need to be at least level 12 to proceed to the next quest. After you reach level 12, talk to Ahtbyrm to accept the next quest: Without a Doubt.