How to write good mystery (like Harry Potter)

In my opinion, Harry Potter and the Sorcerer’s Stone is the perfect archetype for good mystery. It may be simple and straightforward, but that’s what makes J.K. Rowling's first Harry Potter book a perfect example. It’s easy to follow, and it does everything a good mystery should: 1. it keeps you guessing right up to the end, 2. all the pieces fall into place during the reveal, and 3. it rewards repeat readings.

To really understand what makes a good mystery, it’s helpful to compare a good mystery to a bad mystery. The television show Lost is a great example of a bad mystery. WARNING: there are spoilers up ahead, but Harry Potter is almost 20 years old, and Lost ended five years ago, so that "spoiler" warning should expire soon.

The first Harry Potter book has a simple mystery: who is trying to steal the Sorcerer’s Stone and harm Harry? The key to making this a successful mystery is that all of the clues could lead you to the correct conclusion, but the average reader doesn’t see how all the clues fit together until the very end.

All of the clues – put together properly – reveal that Professor Quirrell is the story’s villain. But all of the clues also point to Professor Snape, and that’s the key to making this mystery work: the clues make sense in context and could lead you to the correct conclusion, but the clues also point to a different culprit.

Here’s a great example: someone is using magic in an attempt to knock Harry from his broom during a Quidditch match. Harry’s friends see Professor Snape whispering an incantation, and interrupt him. On their way to stop Snape, the kids have a humorous little bit of slapstick: they accidentally knock over Professor Quirrell in the stands. In the end, it turns out Snape was whispering his incantation to protect Harry, and Quirrell was cursing Harry's broom.

Do you see how this rewards the reader? The clues are all there. An attentive reader could notice that Professor Quirrell was knocked over at the same time that Harry’s broom started working again. When Quirrell is revealed as the villain, that clue falls into place and makes sense. On a second read-through, the reader sees the story through a new lens.

Compare that to the end of Lost. All the clues throughout the series led up to . . . nothing. Readers analyzed a repeated string of numbers, hidden codes, and riddles. In the end, none of their work was rewarded. The “twist” at the conclusion did not follow from the clues, so no attentive viewer could have figured it out, and a repeat viewing has no value. Your new lens changes nothing.

Think of a good mystery as a puzzle. Once the last piece is put in place, you want your reader to see the final picture and say “of course! That’s what this was building to! Every piece fits together perfectly to create this picture!” In Lost, you spent six years painstakingly putting puzzle pieces together, only to have the puzzle ripped out from under you and a new picture put in its place. That’s not how puzzles work.

Your goal is for your readers to say “aha!” when they’ve reached the end. You don’t want to hear a “huh” or an “oh, okay.”

To accomplish this, make sure your clues point to the mystery’s solution.

Now that your clues create a solvable mystery, we run into a problem: Won’t that make it obvious?

That’s where Snape comes in. Your clues must lead to the solution, but they must also point to other possible solutions. Going back to our Quidditch match example, Harry’s friends stop Snape’s incantation at the same time they knock Quirrell over, leading the average reader to assume that Snape was the cause of Harry’s plight.

The reason this works is that Snape is not a simple “red herring.” A red herring exists in the plot for no other reason than to distract the reader from the true solution to the mystery. But Snape is not here as a simple distraction. He’s a fully-developed main character who serves as a source of antagonism to Harry and his friends completely apart from the Sorcerer’s Stone mystery. There’s no better way to tell your reader that someone is not the villain than to have him in your story for no other purpose than to look evil and be the obvious solution to the mystery.

Remember, your goal is to involve the readers in your story. Make them feel like they can solve the mystery if they work hard enough, then reward them at the end with a solution that makes sense, but that they didn’t see coming. Then sneak enough clues in throughout the story that they want to reread it and see how everything fits together.

If you want more examples of great mysteries, check out Agatha Christie’s novels, especially “And Then There Were None.”

What are some of your favorite mysteries? What mysteries ticked you off with their endings? Let us know in the comments.