That only happens the first time, from then on you can see demons all the time. And like I said, it's usually really rare. Demons can only hurt humans if they possess something, and that's pretty hard for them to do.

We also have ways to make that power go away, but most people refuse it. I can't say I blame 'em either. As scary as demons are, it's even scarier to know they're there but not be able to see them.