Adventure Title
Skull/Bone of (the) Circle/Ring/Obelisk/Column

Alternate title
Demon/Devil/Fiend/Horror of the Cave/Cavern

Opening Scene
A ruined keep that is Claustrophobic where they encounter Mercenary soldiers that is/are Looking for a fight

Plot hook and draw
A dying man or woman that is/has Delivered outrageous demands

Plot Concept
Tear a gateway to an ancient era that is motivated by Vengeance

Primary Antagonist
An unfeeling historian who/that is Manipulative

Plot fulfillment and location
Unwilling sacrificial victims from Hyperborea