As promised: Lasers and fog.
The subject is actually standing inside the beam of a party laser. The fog is spread out everywhere so the beam is visible. My brother is standing near the source of the laser with his fingers disrupting the beam, which is where the shadows come from.
I'm using a small LED flashlight from right underneath the subject to light her. The exposure is 6 ish seconds long to get the green laser, and I just guessed the length of the LED lighting.
I spent a fair amount of time recently doing black and white film, just to challenge myself. I'll post some of those shots later.