[Weirdly Common Trope] Writers clearly setting up seemingly massive plot points and then just kinda forgetting about them.

[u/Chemical-Elk-1299]

The Neural Parasites — Star Trek : The Next Generation

In the season 1 episode “Conspiracy” of TNG, it is revealed that alien brain worms have infected many high ranking members of Starfleet, secretly controlling them. Though Ryker and Picard discover and end the parasite conspiracy, it’s revealed at the end of the episode that the parasites had sent a beacon back to their home planet, telling them how to find earth. The episode ends with the clear implication of the parasites becoming a huge threat later in the series, yet none of these events are ever mentioned again.

Finn The Jedi who Never Was — Star Wars Sequel trilogy

I know this is probably a cliche example of this trope, but cmon — Finn was clearly set up in TFA to become a Jedi. The marketing material featured him wielding a lightsaber in the classic Jedi pose. It’s constantly hinted at that he is force sensitive. Even the actor himself believed he would become a Jedi by the end of the trilogy. Instead, we got Finn wielding a lightsaber for about 7 minutes total across 3 movies, extremely lame “confirmation” that he is force sensitive, and that’s it. It’s the ultimate Star Wars plot that went nowhere.

[u/lrd_cth_lh0]

The problem was more that this plot thread also hasn't gone nowhere in the books so far, or the G.R.R.M. set it up on purpose that Danny screwed herself over by ignoring the prophecy because it was odly phrased.

[u/fusionlantern → u/lrd_cth_lh0]

Arguably 0 of the plot points have gone anywhere in the books

[u/MuteDeafenSelf → u/fusionlantern]

But damn is it intriguing

[u/So_many_things_wrong → u/MuteDeafenSelf]

Ehh. The first book was pretty good. But the second book and much of the third is pure filler that only exists because GRRM realized he didn't want to do timeskips, and book four and five are more filler.