“Stranger Things 3” and Chekhov’s Gun
Television shows have come a long way since the late-1940s. Sitcoms and serials didn’t necessarily have the amount of world-building that we see today. Each week, the audience would get a single story that would resolve itself by the end of the episode. On rare occasions, there would be a two-part episode covering a larger plot, but it would always return to the status quo. In the early-2000s, TV shows started to become more movie-like. Shows like Alias and LOST would use the full run-time of each episode to advance the larger narrative of the story while also exploring smaller arcs to develop the characters.
The trick with viewing a show released an episode at a time over a couple of months is that much of the details had to be memorized so the thread connecting them together would be understandable. This is why you’d usually see a “previously on [BLANK]” section at the start of these episodes to remind you...