Ex Oblivione: Delta Green RPG - Rules of Play says:
The past is bloody teeth…which still hunger. Something evil has stirred in a tiny desert town. It haunts the area like the thin clouds which taint the sky each morning, turning the sun blood red. Sometimes, it is thick and choking. Other times, it’s a skein so barely there it’s easy to forget it exists at all. It holds the people in check. Only black flattop and sun devils wait for them, each and every day. But few ever leave. And the evil around them can no longer be denied. A gruesome crime draws Delta Green to the haunted desert. Bodies have been ritualistically mutilated. Bizarre words carved into the drywall speak to the insanity of the killer—and, to Delta Green, the urgency of the investigation: HOME DAGON HOME HOME YHANTHLEI SEA TO THE SEA. “Ex Oblivione” is a complete scenario for Delta Green, the role-playing game of Lovecraftian horror and conspiracy.