You go to inform the Zundu that you have defeated Bismarck while Garlond Ironworks repairs the Enterprise.

Requirements

This quest is available if you have completed the quest Bolt, Chain, and Island.

Starting the Quest

Talk to Alphinaud in the Sea of Clouds to begin 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.

Speak with Alphinaud

Talk to Alphinaud to proceed.

Speak with Cid

Go east to where the orange arrow is pointing in the minimap. (If you have not yet unlocked flying here, go north from Alphinaud and Lucia and follow the dirt path that winds through the area. It will lead you to some more wooden stairs, and at the top you will find another dirt path. Go along it until you can go southeast to the quest icon on the map.) Talk to Cid to complete the quest. There will be a cutscene.

Next Main Scenario Quest

After you complete the quest, talk to Cid to accept the next quest: One Good Turn. 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.