After you deliver the antique dagger to Fufulupa, he needs you to help his fellow Brass Blades.
This quest is only available if you started the game in Ul'dah, you have completed the quest Passing the Blade, and have reached level 13.
Starting the Quest
Talk to Fufulupa in Horizon in Western Thanalan to begin the quest.
Speak with Totoruna
Go west through the tunnel from Horizon to reach the quest destination. Talk to Totoruna to complete the quest.
Next Main Scenario Quest
After completing the quest, talk to Nunuzofu to accept the next quest: Storms on the Horizon.