This effect is called Pepper's Ghost. If you've been on Disney's Haunted Mansion ride, the ballroom scene was done with a pepper's ghost illusion. The idea is you set up a normal haunt scene, but in the scene a ghost appears. In this case we had our pirates with their loot, and a ghostly skeleton appears. One of the better parts of this was our Pepper's Ghost was a real person, so it could appear and interact with the trick or treaters. We've found that the interactive stuff is what the TOT's like the most. We also did a pepper's ghost for our 2004 haunt, but it didn't turn out as well. But more info on the effect can be found on the page. 2004 Pepper's Ghost