A Summoning Stone

Exploration Stage: Heirs’ Villa
From: Robert Luxmore
Description: The scroll says that all Luxmore family members can be summoned by a stone. But we only summoned our servants with a bell... hold on! We used to have a special bell adorned with crystals. Where is it now?
Completed: Yes, that’s the bell. My father kept it in his study, but I never heard him ring it. Well, no one can stop me from ringing it now... Did you hear that? Something’s resonating.