From NYT bestselling author Dave Farland:
Have you ever noticed how a television or movie series can grab you at the beginning but feel tired and “old” after a few episodes?
I loved Harry Potter when it came out, but for me at least, it became stale. I quit reading the series at book six, deciding that I’d rather see the movies, but even the last couple of movies didn’t really grip me.
. . . .
There are two reasons why tales go stale, I’m convinced. The first one is that when we first see a great movie or read a great book, we go into the story with a lot of questions. Who is our protagonist, our antagonist, our cast? What are their interesting quirks? What is the world like? What are the major conflicts? What obstacles need to be overcome?
A good writer will look for dozens of way to keep you wondering. But eventually, the questions all have to get answered. Sure, you might be able to string the audience along for a while, the way that the writers did with the television series “Lost” and “Heroes,” but eventually you have to answer the question “What’s going on?” or the audience will walk out on you. With both of those series, I felt that the writers were cheating, and I walked out early.
Once you let us know who your protagonists are and their conflicts, you enter a dangerous part of your story. You see, very often, as an author we use suspense and mystery as our draws, emotions that drag a reader into a story.
But once the reader knows what’s going on, the reader silently begins asking the question, “Do I care?”
Readers will only care about a story so long as the protagonists are likeable (what makes a protagonist likeable is a large topic in itself), and the protagonists must be going through some conflicts that grip the reader. Such questions as “Will Dan and Gina fall in love?” “Will Gina catch her mother’s killer?” and “Will Dan ever overcome his drinking problem?” all need to be answered. Once they’re answered, that story is done—forever.
. . . .
With mysteries, you’ve got a little more leeway. You can have a detective solve a crime, catch a criminal, have that criminal get released from prison or escape somehow, and then have your detective track him down again. But you can’t do it endlessly. If your killer escapes justice once, shame on him. If he does it twice, shame on your detective. At least in American fiction, the criminal would need to die after a couple of movies.
Of course, the detective can solve a new crime—as with Sherlock Holmes or Die Hard—but eventually even the most intriguing detective grows stale.
My point here is this: eventually, the story needs to be defined and the conflicts need to be resolved. Once those two things happen, your series is done. Period.
Link to the rest at David Farland