I need some help. This can be real-real, or Michael Crichton-real. I'm writing this thing where a cult is kidnapping women and possessing them with evil spirits. There has to be something in the environment or in their houses that either the women are using for protection, or the members of this cult are using to their advantage. I'm having trouble figuring out what that something is. Right now, I've got nearby copper mines. Copper is one of the seven metals of alchemy, and generally thought to channel positive energy. The way I'm working things right now, the women knew they were targets, and were living near abandoned copper mines as a sort of shield from the cult members looking for them. It works, but I feel like there's probably something better I could use. Anyone know of anything I might be able to research a bit?