After you deliver Nunuzofu's message to Raffe in Crescent Cove, Merilda has some gossip to share.
This quest is only available if you started the game in Ul'dah, you have completed the quest Storms on the Horizon, and have reached level 14.
Starting the Quest
Talk to Merilda in Crescent Cove in Western Thanalan to start the quest. There will be a cutscene.
Speak with Captain Baldewyn
Go north and you will find Captain Baldewyn. There will be a glow around him, indicating another instanced battle. Check on him and there will be a cutscene, and then the battle will ensue.
Solo Duty: Oh Captain, My Captain
Stay near Fufulupa, because he can heal you if needed. Start by defeating the two Brass Blade archers off to the sides. Then focus your attacks on Ser Baron von Quiveron IV Esquire. When he is down, attack Baldewyn until he is defeated.
Speak with Fufulupa
After the battle, there will be a cutscene. After that, go east to Horizon and talk to Fufulupa to complete the quest.
Next Main Scenario Quest
After completing the quest, talk to Fufulupa to accept the next quest: Secrets and Lies.