Before you proceed to the forest to meet with Y'shtola, the Exarch asks you to procure a gift for her from the ruins of a church.
This quest is available if you have completed the quest A Party Soon Divided.
Starting the Quest
Talk to Urianger in Lakeland to begin the quest.
Survey the Area
Go north to the orange circle on the map. Go to the northeast part of the orange circle where Urianger is standing, and go down the stairs. Check on the sparkling Destination to proceed. There will be a cutscene.
Search for the Timeworn Tablet
Check on the sparkling Destination. Zoom in and move the crosshairs over the right side of the altar that Urianger is standing behind, where there is a Timeworn Tablet. Follow the on-screen instructions to Execute Confirm. There will be a cutscene.
Speak with Urianger
Talk to Urianger to complete the quest.
Next Main Scenario Quest
After you complete the quest, talk to Urianger to accept the next quest: Into the Dark.