Mad scientist lab and drink / hors d'oeuvres location. This will give people a reason to go in, and can make it memorable with enough little gimmicks.
Platters of goodies done up as body parts / bugs / alien bits and pieces - placed and labeled all around the lab.
Ice chest or two with beverages - perhaps styrofoam coolers with your fog channeled into backs of them, to have fog creeping out - people have to reach into the fog to get their drinks.
Maybe some motion / sound activated props placed around to give people a startle now and then.
Black lights.
Different sized skeletons become a series of failed attempts at making a monster - last cage in line has bars bent out from inside, since the monsters has escaped and might still be somewhere in the lab (prop and strobe light in closet, use a simple wall outlet remote control (like the kind for Christmas tree lights) in your pocket to light it up whenever you want.
Platters of goodies done up as body parts / bugs / alien bits and pieces - placed and labeled all around the lab.
Ice chest or two with beverages - perhaps styrofoam coolers with your fog channeled into backs of them, to have fog creeping out - people have to reach into the fog to get their drinks.
Maybe some motion / sound activated props placed around to give people a startle now and then.
Black lights.
Different sized skeletons become a series of failed attempts at making a monster - last cage in line has bars bent out from inside, since the monsters has escaped and might still be somewhere in the lab (prop and strobe light in closet, use a simple wall outlet remote control (like the kind for Christmas tree lights) in your pocket to light it up whenever you want.