Astronomers are closing in on the proof they've sought for years that one of the most destructive objects in the universe - a supermassive black hole - is lurking right in the center of our own galaxy. Could it flare up and devour our entire galactic neighborhood? NOVA mounts a mind-bending investigation into one of the most bizarre corners of cosmological science: the truth about black holes. From supernova to event horizon, the dark secrets of supermassive black holes are revealed through stunning computer-generated imagery, including an extraordinary simulation of what it might look like to fall into the belly of such a beast.