Davyd will find a crystal for you if you help him deal with the undead that now haunt the area.
This quest is available if you have completed the quest The Reluctant Researcher.
Starting the Quest
Talk to Davyd in the Isles of Imbra (accessible via the Ferry Skipper in Aleport in Western La Noscea) to begin the quest.
Speak with the Adventurers
Go southeast from Davyd and talk to Ahlduwil, Erapi Taropi, and Louis.
Report to Davyd
Go northwest and talk to Davyd to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Davyd to accept the next quest: History Repeating.