The potential for surprises come in many forms when writing a story. Sometimes, or probably most of the time, surprises are pre-planned. As the writer, you think of plot secrets to reveal layer by layer or cliffhangers for chapter endings. You pick the right moment to reveal them with optimum effect, be it the next page or holding out til the end. That's the fun part, that rubbing your hands together in anticipation setting up the surprise and the payoff during the delivery of your insider information. You know, if all works right, the reader is going to sit back and think - - with various emphasis on the exclamation point -- "I didn't see that coming!"
Other times, the surprise is on you. The characters are up to something, but you're not sure which direction they are going. In their own time, they are going to reveal their inside information and leave you sitting back and saying, "I didn't see that coming!"
This form of surprise happens in all forms of writing actually, including music. Not so long ago, on a PBS special honoring him with the Gershwin Award, I heard Paul McCartney talk about the creation of one of his songs. With lovely, almost humble humor, he first joked (maybe?) that the original lyrics were something like "scrambled eggs, oh how I love your legs." LOL But it was the melody - - a melody, he said, that seemed so familiar he had to ask everyone around him, "where have you heard this before?" Over and over he asked the question. It had to exist. But no one knew. No one had heard it. So, after a considerable time, he said with a shrug, he had to claim it for his own. That song: Yesterday.
(Now I hear it. Scrambled eggs...oh how I love your legs.)
But the best part of his story was the mystified awe in his voice and expression when he gave the only explanation. Magic.
I got a little shiver when he said that. Even I, somestimes if I'm very lucky, have felt that magical feeling that an idea is plucked seemingly out of the air. Creation is magic.
Both forms of surprise are vastly different. The magic kind leaves you humble, gifted with something so new but familiar you feel a slight trepidation about claiming it as your own. On the other hand, the insider information kind makes you anything but humble, skipping around with a childish 'I've got a secret' glee.
Both are wonderful things.
Of course, sometimes we run out of the pre-planned surprises. Then we wait for magic. But the magical muse is fickle. Write it out anyway. You never know what may fall from the sky.