A star collapses in a supernova and leaves behind a black hole, gravity so concentrated that light cannot escape it. The film builds from that single event outward, asking how common these objects really are: astronomers estimate roughly 125 billion galaxies in the visible universe, and current survey data suggests nearly every major one, including the Milky Way, hides a supermassive black hole at its center. Researchers using the Sloan Digital Sky Survey and the Hubble Space Telescope explain how they infer a black hole's presence without seeing it directly, tracking the way its pull distorts orbiting gas and stars. The film spends time on the Milky Way's own central black hole, describing its scale and asking what keeps its gravity from eventually pulling in everything around it, our solar system included. Along the way it separates the science from the science-fiction image of black holes as tunnels through space and time, using event-horizon physics to explain why nothing, including a hypothetical passage to anywhere, survives the crossing.