The process of crafting a movie script that's nuanced without feeling wildly overstuffed is an incredibly delicate one - to support the overarching plot with interesting, character-driven subplots which actually pay off in satisfying ways.
And so it's little surprise that so many films fail to follow through with meaningful minor plots alongside the admittedly more important big-picture payoff.
Not quite nailing the mark is one thing, but sometimes movies set up an enticing side-plot only to straight up throw it out with the bathwater with no added explanation.
These 10 movies are all wholly guilty of explicitly establishing attention-grabbing plot points which the audience quite reasonably expected to see paid off later on, only for no such resolution to ever arrive.
And so these subplots, tantalising as they are, are still left dangling in the wind today, with fans forced to speculate on what the outcome actually would've been.
Ambiguity can be satisfying in its own way, but given how blatantly a payoff was implied to be happening for these subplots, it was both bizarre and frustrating that they ended up going nowhere at all...
10. Quicksilver Is Magneto's Son - X-Men: Apocalypse
X-Men: Apocalypse is, to be kind, a big 'ol mess, and one of its most intriguing, potential-rich character threads gets set up only to fall by the wayside by film's end.
The film establishes in quite unambiguous terms that Quicksilver (Evan Peters) is the son of Magneto (Michael Fassbender), and it appears as though the story is building towards some sort of emotional connection between the two at film's end.
Bafflingly, despite the obvious potential for Quicksilver to play an emotional hand in bringing Magneto back from Apocalypse's (Oscar Isaac) seductive influence, no such scene ever takes place.
This wouldn't have proven quite so frustrating had it not also been completely ignored in the sequel, Dark Phoenix.
And given that Fox's X-Men franchise is now effectively done, fans will never get closure on this plot point. Peters himself called the situation "sad" and tried to lend some context to it:
"Originally I think they were going to have Quicksilver tell Erik that he was his son but it felt a little forced in a situation... Would [Quicksilver] want [Erik] to know that as [Erik's] destroying everything in that moment, and is that going to be enough to turn [Erik] to the good side? So it was kind of like, would you really want to put yourself out there in that situation? You might wanna wait until you're having some coffee or chilled out and tell him."