By Wook Kim
October 31, 2008 at 05:30 PM EDT

I don’t believe in ghosts, but this footage — captured on a security camera in a London dungeon — almost makes me want to rethink my position. Look for some movement in the upper-right panel around the 0:43 mark. This is pretty scary stuff — those easily frightened should probably not watch. You’ve been warned. Oh — and Happy Halloween!