The House of the Deceased is a Soul Network formed by powerful Spiritual Bodies similar to Relay Spirits. It has no owner, so it can connect to the souls of anyone.
It's operated by the Undead Guild, and information exchange is carried out through a feature similar to a ledger. People can post information, make purchases, offer rewards, announce, and so on. Its functionality is akin to the bulletin board that used to be in front of the Mercenary Guild.
This Soul Network has been operating smoothly for over a thousand years, and the vast majority of people, from a very young age, know about its existence and take it for granted.
Merchants, mercenaries, politicians, and officials from all sides have grown accustomed to using it as a window and platform for external affairs. In some small places where there is no regular security force, bounties are posted to capture various criminals, greatly shocking people from all walks of life.
