Once upon a time, when I was in my late teens, my party trick was seances. I know that sounds kind of weird, but it’s true. We used to improvise an ouija board, use a (clean) scotch glass as the focus, and then have at it. And for some reason, whenever I was touching the glass, it would glide around the board like an ice skater on a rink — even if I wasn’t really paying much attention.

I’m pretty sure my friends thought I was pushing the glass around, although they never accused me of it. And although I wasn’t doing anything deliberately, I sometimes wondered if there was something subconscious going on, because I often “heard” the word reply in my mind as the glass started spelling it out.

During one particularly freaky incident, one of the guys taking part had brought along what he claimed was a…