Prior to this posts, I've discussed the history of the universe, as we currently can observe and understand it, up to present day (give or take a few million years). If you missed those, here's Part I and Part II, which will catch you up. But really, as cool as the history of the universe is (and it's pretty neat), I wrote those posts so that I could write this one, about what happens next. Fair warning, it's fairly bleak and existential, albeit fascinating. Now, with Halloween around the corner, I've got a scary story for you: how the universe will (likely) end.