As usual, built for a thing; more on that thing as it develops.
It took 90 shots to find one I liked. Either the fog was too thick, the camera wouldn't focus, or light was reflected. The punch line is, the end result is something that would've taken maybe 10 minutes in Photoshop, but I'll take in-camera effects over post-production any day.
*Inspiration for the fog effect is Legohaulic's lovely haunted house.