From Introduction:
Th e nobles of Ardoussarlis were rich beyond compare. But this vast wealth did not make them value their possessions any less. On the contrary, it was their immense greed that built their empire to begin with, and they had no wish to lose their belongings to anyone, not even the grave itself. So they turned to sorcery for ways to protect their belongings. One defence they developed was the demongate shrine — a portal that summons demons to protect their vaults, their tombs, and even (sometimes) their homes.
Every shrine looks like a fireplace, topped with the head of some fantastic or gruesome beast. These animals once indicated which noble house the shrine was built for, but subtleties such as these are no one’s concern anymore. The trap is simplicity itself: if you are not welcome to pass the shrine, but do so nonetheless, a shrinegate demon emerges to assault you until you either leave or die. For the unsuspecting victim, of course, it is the most horrific turn of events! Moreso if they are dragged off to some hell as yet unseen by all on Earth, save for a few Ardoussarlian wizards, as sometimes happens. Or so they say. But then again, no one said looting this city would be easy.
These days, demongate shrines can be found in unlooted tombs,
subterranean passages, and in the ruins of sorcerous workshops. Those locked away remain pristine, but those along routes well-travelled often have coins and candles (and blood, long-dried) scattered on the floor around them.