For standalone stories, that's often stuff we don't care about. The killer is caught, and we're content to know everybody goes back to their normal lives. The guy and girl get together and live happily ever after (or maybe not, but we're content to know they start the rest of their lives together).
But what if it's part of a series? How do you provide an ending that satisfies the reader, while leaving gaps open for a sequel? I think it's related to the promises I talked about last time. One of those promises is that all the reader's questions will be answered, or at least touched on.
As an example, let's look at another classic: The Empire Strikes Back. Going into the climax, what are the viewer's questions?
- Will Luke escape the trap?
- Will Luke rescue Han, Leia, and the rest?
- Will everyone survive?
- Who is the "other hope" Yoda mentioned when Luke left Degobah?
The fact that we don't know who the "other hope" is doesn't bother us because it's not a Big Question. It's mysterious and intriguing, but it's not vital to this story. These are the kinds of questions that can (usually) be left unanswered without causing an uproar.
But what about Han? The question "Will everyone survive?" is a always a Big Question for action/adventure stories. So why is this okay? I can think of three reasons.
First, we know there will be a sequel. If Empire were pitched as a standalone, people would have been more angry about Han. Lesson: Don't leave big cliffhangers unless you're sure you'll be able to write the sequel.
Second, Empire gives us lots of clues as to the direction the story is headed after the ending. We've been assured that Han is alive and safe in the carbonite. Lando has earned our trust, and he and Chewie are going after Han. Luke says when he's well, he will do the same. Lesson: Give the reader clues so they can piece together their own ending.
Third, the story of Empire was not about Han. Empire was about Luke learning to be a Jedi, and what it meant for him to face Darth Vader. That story was resolved satisfactorily. But if Han had been frozen in carbonite near the beginning of the story, and most of the movie was about trying to save him, then we'd be pissed if at the end he wasn't either rescued or dead. Lesson: Determine what story you're telling, and resolve that story completely.
Finally, I want to say that ambiguity is dangerous. There probably were some people who were angry at the way Empire ended. With ambiguous endings, somebody will always be upset that not all the threads were tied up. Everyone has their own threads they care about more than anyone else, and if you happened to leave their thread hanging, they'll be upset.
So I guess the lesson is: Be ambiguous at your own risk.