Aideen wants you to bring back a chunk of the mysterious rock that is said to house the rancor of the murdered maidens.

Requirements

This quest is available if you have completed the quest Ziz is So Ridiculous.

Starting the Quest

Talk to Aideen in Fallgourd Float in the North Shroud to begin the quest.

Throw the Firesand Stick at the Rock

Go to where the orange arrow is pointing in the minimap to find the quest destination. You will see a glowing spot on the ground. Use the Firesand Stick from the Key Items section of your inventory, or via the icon next to the quest name in the list of active quests, then move the targeting ring onto the glowing spot to use the Firesand Stick.

Gather the Lightning-Aspected Crystals

There are five Humming Crystals nearby. Pick them all up to proceed.

Deliver the Lightning-Aspected Crystals

Go back to Aideen in Fallgourd Float and talk to her to hand over the crystals and complete the quest.

Next Main Scenario Quest

After you complete the quest, talk to Ivaurault to accept the quest Seeing Eye to Winged Eye if you haven't already. If you have already completed it, talk to Medrod to accept the next quest: Power of Deduction. There will be a cutscene.