Black Hole Apocalypse, a 2018 science documentary presented by American cosmologist Janna Levin about the most mysterious known objects in our Universe.
First described by Stephen Hawking in his famous publication "Occurrence of singularities in open universes" in 1965, "black holes" gained there name not only for nothing being able to escape them, even light, but also because there is very little we know about them.
The only information we know about black-holes is from information gathered before the event-horizon, which is the point where light can no longer escape its gravitational pull. Beyond that point, it is likely that we will never observe what actually happens to the matter getting pulled in, though it can be explained using mathematics.
The very foundations of reality breakdown in the centre of a Black Hole; in mathematics, it is called singularity and it basically means that known physics can no longer describe what is going on. The "Black Hole Apocalypse" documentary attempts to visualise black holes.