At first, the tornado is nearly invisible. Against the sky, it’s white on white. — Greg MacGillivray

If you’ve ever lived in a tornado-producing region, you’ll know the visceral terror of a tornado dropping out of the sky unexpectedly, changing course on a whim, and damaging some things beyond recognition while sparing others without any apparent rhyme or reason. There is very little about a tornado that makes sense, but there are few things that feel so very, very real in the moment.

Does everything in your story make sense? That’s good. But does it also all make just a little too much sense? Is it a little too plotted out? Is there anything unexpected in there? Is there a bit of chance or serendipity within the plot, characters, setting or timing that gives your reader a jolt, even if it doesn’t significantly impact the main storyline?

Would a rain-wrapped tornado popping unexpectedly out of the sky into the soybean field next to your main character as he drives through Iowa on his way to that new job and dissolving almost as quickly as it arrived make your main character sit up a bit straighter and pay more attention as he drove cross-country? Your reader surely will.

What memories, for example, would be triggered if you saw that the pharmacy cashier had the same unusual name as a grandparent or a former neighbor from childhood? Do you create meaning out of the experience or write it off as a fluke? Do you continue to think about it at random times and always wonder a bit, or do you forget about it straightaway? What do your characters do with them?

While coincidence should never get your character out of trouble, it can be used to great effect to get them into trouble. What chance event occurs in your story that upends their world?