And with “The Big Bang” — which first aired on June 26, 2010 — Moffat achieved that by delivering a story that didn’t try to go bigger than previous finales at all. Instead, “The Big Bang” suggests the end of the world could happen in the cramped recesses of a museum, and maybe, on the rooftop. While prose time travel narratives have often employed this kind of effect-before-cause, it’s really hard to point to a mainstream sci-fi phenomenon that is so brazen about paradoxes as the Moffat era of Doctor Who. “The Big Bang” was the dawning of a new golden era of Who, one full of big feelings and small, realistic human problems. Doctor Who Season 5 (2010), “The Big Bang” streams on HBO Max.