From PathfinderWiki

Gravehearst was a town in the barbarian kingdom of Sarkoris. During the First Mendevian Crusade it was attacked by an overwhelming force of demons from the Worldwound. The local shamans had created a powerful magic item to defend the town against the demons, but found themselves unable to activate it.

Also in the town at that time was a force of crusaders led by Saint Clydwell. The shamans gave him the item to guard. Saint Clydwell died fighting a powerful demon, but his death created a powerful magical effect which banished all the demons from the town and also empowered the magic item, creating the Demonscope. Unfortunately for the people of Gravehearst, the banishing of the demons was only temporary.1


  1. Stephen S. Greer, & Tim Hitchcock. (2008). The Demon Within, p. 29. Paizo Publishing, LLC. ISBN 978-1-60125-076-6