To aid your investigation, Minfilia will introduce you to an Ala Mhigan member of the Scions.
This quest is available if you have completed the quest Foot in the Door, and have reached level 26.
Starting the Quest
Talk to Minfilia in the Waking Sands in Vesper Bay in Western Thanalan to begin the quest.
Speak with Haribehrt
Leave the Solar and go north to the storage area, where you will find Haribehrt. Talk to him to proceed.
Speak with Albreda
Go to Quarrymill in the South Shroud and talk to Albreda to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Meffrid to accept the next quest: Killing Him Softly. There will be a cutscene.