There is a common trope used to create continuing storylines for television shows.
It's this: have a big bad mastermind behind the bad things that happen as the hero battles the villain of the week. In the background, there is a mastermind villain, like King Koopa in the Mario Brothers video games, behind most of the villain-of-the-weeks and most of the bad things that happen in the background. This villain gives you a continuing storyline.
Now, I am not criticizing this trope. It can be done as well as any basic good guy-vs. bad guy hero type of story. It can be done as well as it was in the marvel movies through the final battle with Thanos.
There are critics that give the credit for developing this trope to Joss Wheadon, creator of Buffy the Vampire Slayer.
Sorry to disappoint you, but continuing storylines like this were around long before Buffy.
The big bad mastermind archvillain-of-the-season trope is surely inspired by things like King Koopa in the Mario brothers video games.
But as for television shows, continuing storylines were done as early as The X Files and Babylon 5
And were perfected by Babylon 5.
Whereas Buffy is credited with introducing the pop song version of this kind of continuing storyline
Babylon 5 had already given us the Beethoven's 9th version.
This was no simple merely a mastermind villain in the background story.
This was a narrative worthy of the legends of literature, unveiling layer upon layer of ancient past and wider world, going into ideas much deeper than simply fighting bad guys, involving deep philosophical ideas worthy of the legends of literature.
I won't spoil it for you.
Let's just say that it doesn't dissappoint like the X Files does.
Especially if you want something that means more than CSI and modern grimdark stuff does.
This is the true prototype of the television continuing storyline, done on a level that the writers of early-2000's non-sci-fi television dramas could not even imagine.
With deep ideas, not just shallow intelligence like CSI and the like. Not just trying to outsmart someone for no good reason. And something uplifting, to give us hope and courage in the face of adversity, like the Harry Potter stories do, while celebrating our humanity.
God loves you!
Sincerely,
David S. Annderson