Dark Matter
The first film that comes to mind when talking about dark matter is The Blair Witch Project. The witch is never actually shown. As a device, dark matter, in stories create a lot of suspense. It works especially well in the horror/thriller genre. And you can see that it works. Think about any really good scary movie. They almost always wait before revealing the monster/killer. They may show killings, but the face is always hidden to build anticipation and suspense. Subsequently, the reveal should be scarier. Though the flip side may be true as well. The anticipation may build to the point that the reveal is quite lackluster. I know for me, when I'd see a scary movie as a kid, I stopped being afraid after I saw the killer/monster. But the parts leading up to it were scarier. I think that plays can use dark matter to just generate more interest and excitement. There is a lot you can do on film that you can't recreate on stage. So, using dark matter as a device seems appropria...