[Crowley considers that question for a moment, regarding his drink while he decides how honest to be.

Archer has already seen him attempt to use blood magic, so he can't exactly pretend he's normal. And also, no one will believe Archer if he tries to spread rumors.]

For my money, it's some kind of pocket dimension. I've got a... vague understanding of the theory, but not the application.

[He figures they're presently outside time, which is something he could do, if only for a short time, but he's never tried it before, doesn't know what it would look like.]

What I do know is we should be terrified of whatever has enough power to do this.