The Good, The Bad, and The Surprise Ending
I don’t believe in rules for novels. There are always so many exceptions and so many different ways to break the rules that nothing as far as I know holds up. But as a general rule of thumb, I believe that when you’re writing the end of your novel, you should give the readers what they’re more-or-less expecting. This does not mean to go with the most predictable ending. It means, simply put, that if you’ve been building your novel toward a dramatic ending revelation, your main character should not wake up and find out that it was all a dream.
There are many ways to use surprise endings that would work. If a character has been haunted by weird dreams, maybe he wakes up in the end to find out that they weren’t really dreams at all but foreshadowings of his future. Or maybe a super villain breaks down not because he’s really the hero’s father, but because now the very plans that he was going to execute on the hero will suddenly be used on him instead, and he never saw it coming.
When deciding on an end for your novel, it’s a good idea to write out all possible alternatives before choosing which you’ll stick with. Consider both the most surprising and the most mundane, and think about what you’ve been building toward. Somewhere in there is the perfect ending for you–a nice snap that not only satisfies but leaves your audience wanting more, and leaves you with more power and authenticity as an author.