How to Write a Mystery (from the author of 16 books!)

If you’ve ever tried your hand at crafting a mystery, you’ll know it’s not the easiest thing to do. It’s not rocket science, of course, but it still takes effort, planning, and understanding what needs to happen and when. That’s probably why the mystery genre is considered a difficult one to write in.

Consider this article your crash course on how to write a mystery. After all, it would take more than one post to perfect the art of writing mysteries–by the way, point me to the person who’s done that apart from Agatha Christie or Sir Arthur Conan Doyle. But, there are simple things you must get right if you want to provide a satisfying read for mystery lovers.

In this article, you will learn:

• How to pick an antagonist.
• Why motivations are important in mysteries.
• What red herrings are and how to use them.
• How to intertwine your main plot with your side plot.
• What not to do in a mystery.

Disclaimer: I’m primarily a cozy mystery author, so I’ll be framing this around that genre, but the basic techniques provided here will work for other sub-genres too.

Step 1: Craft Suspicious Characters

The basics of crafting an interesting character in any story is just about the same. In learning how to write a mystery, the difference is you get to make them suspicious. And that’s fun. Mystery and suspense are based on the unknown and on potential. The kind of potential that the friendly old lady down the street has to murder her next door neighbor… and all over a recipe.

Never underestimate the ability of a human being to do the worst to get what they want. That sounds negative, sure, but that’s the type of attitude you’ll use when crafting your characters. In your mystery, you want all of your characters to have a hint of mystery and suspicion. (i.e. you want to give them traits that make them seem suspicious to the reader.)

After all, if your antagonist, the murderer, is the only suspicious-seeming character or even the only innocent-seeming character, your reader will figure out whodunit, right away. The best emails and reviews I get from readers are always ones that say something along the lines of, “I didn’t figure it out until the end!”

The only character who won’t be suspicious is your main character. And you should follow the same steps you would for character creation for any other protagonist.

Your protagonist must have:

• A conflict and stakes. Jessica is recently divorced and doesn’t want to trust anyone–she’s focusing on her little bakery in the new small town she’s moved to. But when one of her customers drops dead after eating a donut in her store, Jessica’s bakery might be in trouble. If Jessica doesn’t open up, she’ll never solve the murder and saved her bakery.
• A goal. Jessica now wants to overcome her internal conflict of keeping to herself as she uncovers the truth about the mystery by liaising with the other people of the town.
• A growth arc. Jessica overcomes her conflict by the end of the book. She’s starting to fit into the town. She’s also solved the murder mystery with lots of hiccups along the way.

The fun part comes next. You get to craft the cast of suspicious characters, all of whom might just have killed the victim. Or they may have had a reason to do so to get back at our protagonist, Jessica.

The steps for crafting your cast of suspicious characters:

1. Write a list of characters you want to include. Make it varied and interesting. From the granny down the street to the enemy baker across the road who’s just opened up shop.
2. Give each of them a minor goal. Granny’s goal is to get the secret donut recipe from Jessica. She wants it because she’s planning on opening a shop of her own.
3. Give each of them a flaw. Her flaw is she’s duplicitous. She’s a lovely woman, but she’s got a sordid history–including a rap sheet for theft. She’s lived a hard life and wants to follow her true passion for baking.
4. Give each of them an enemy. Granny’s enemy is the new baker in town who wants the recipe too.

As you do this for each character, you’ll start crafting motivations for murder. It could be that Granny is the murderer, or that it’s the new baker across the street. Or it could be someone else. Don’t be shy about creating a subplot that runs alongside the main plot. Maybe, Granny’s not involved in the murder at all. But she sure seems suspicious, and she’s definitely been snooping around the bakery.

Step 2: Decide on Who’s Dying, Why and How

Probably one of the most important steps in learning how to write a mystery is deciding who’s going to kick the bucket. Or have their bucket kicked.

In cozy mysteries, the victim is usually someone who is hated by all in the small town. This serves to complicate things for your sleuth–they’ll have loads of people to suspect and investigate during the course of the unraveling mystery.

But you don’t have to stick to that. You can pick anyone in your list of characters to become the victim. You just have to have a clear idea as to why. What part of their conflict or goal makes them the perfect target?

This is where you connect your characters and their motivations. You can make the victim innocent of misdeeds or hateful and mean. Perhaps, they’ve been stalking their ex-wife or husband? The ex-wife’s new partner takes offense to this and murders them. Naturally, you’ll write down all of this information, but you won’t divulge it all upfront.

How the victim is murdered is important too. You can use the murder weapon as a clue for solving the mystery, whether it’s a gun, a poison, a knife or a blunt option. However, make sure to do your research on your chosen weapon. Readers are sticklers for certain things in mystery–you’ll get away with a sleuth who interferes in police work, but you won’t with a poison that doesn’t have the correct side-effects.

In short, you must have a reason for why the victim is killed and how they’re killed, when and where. Kind of like writing Clue. You note all of this down, and intertwine the information into your story by dropping clues to your protagonist.

Actionable steps:

1. Pick your victim.
2. Note down why they were killed, and connect them with several suspicious characters with reasons why those characters may have wanted to kill the victim.
3. Select a murder weapon and research it.
4. Give certain characters access to the murder weapon. (i.e. A chemist has access to certain medicines, but so does his assistant or the receptionist who may have broken into his private store.)

Better Keywords & Categories Fast

See why over 47,000+ authors and publishing companies use and love Rocket to help them sell more books.

Get Publisher Rocket Now!

Step 3: Pick an External Conflict

This is kind of an optional step. It depends on how long your mystery is going to be. In cozy mystery, books usually range from 20,000 words to 70,000. If you’re writing a longer story, you’ll need more intrigue, more conflict, and more plot.

This is why I’ll generally pick out an extra external conflict to include in the story. Say we use Jessica’s bakery as an external conflict–she’s being stolen from and things have been going missing in her apartment above the store. What could it mean?

The theft and the murder can be unrelated, or they can be part of the same motivation for the death of the victim. That’s up to you to decide. You can include several sub-plots for characters who Jessica is friends with too.

Perhaps, her new friend is being stalked, or has recently come into money and some of it has gone missing. Or she’s just broken up with an ex-boyfriend, who keeps threatening revenge on the bakery. All of these subplots add up to equal little clues.

The trick is to make the clues of one subplot connect with the main murder mystery. For example, Jessica is suspicious of the theft in her store, and when someone breaks in and steals her journal, she’s not sure if it’s the thief or the murderer.

Important to note: you don’t have to tie off every subplot with a neat ending as you close the book. You can leave some of them open for further exploration in the series. But, you should always give the murder mystery a satisfying conclusion, and your protagonist resolution of their current conflict or goal. Jessica has saved her bakery, she throws a party with her friends afterward to celebrate.

Actionable steps:

1. Write up a list of external conflicts you want to use in your story and how they connect to each character.
2. Pare the list down to one or two subplots.

Step 4: Write up a List of Clues

Another fun step!

Here, you get to write down all the clues that pertain both to your subplot and your main plot. You’ll do this by identifying the crime scene and the clues that are already present there. Since you have the inside edge–you know why your victim was killed and by whom–you can plant evidence over the course of the story that will redirect your protagonist.

You can also plant false evidence, or clues that make it seem like someone else commited the murder. These are called ‘red herrings’ — and they must be believable. All your clues and red herrings have to make sense, after all.

Motivations and clues tie in with each other. Granny wants to get into Jessica’s bakery, so it would make sense that Jessica would walk in on Granny rummaging through her things. Granny can make an excuse, but Jessica will have her suspicions–is Granny the murderer? We know Granny isn’t, but Jessica doesn’t–that’s a red herring that makes sense.

And now, because Jessica believes that Granny might have something to do with the murder, she’ll start following her and unraveling more of the mystery that is Granny’s motivation. Ultimately, she’ll hit a brick wall when she realizes that Granny can’t possibly have commited the murder… until Granny gives her another clue that leads Jessica onto the next suspect.

Actionable steps:

1. Write down a list of clues that connect the characters to the crime scene or make them suspicious.
2. Organize the clues in the order you want them to happen. (i.e. Jessica finding Granny in the bakery after hours. Jessica follows Granny and finds her meeting with Jessica’s enemy etc.)
3. The list doesn’t have to be exhaustive, but it must make sense and tie into your murder and sub-plots.

Step 5: Outline Your Story

I’m not going to go into the outlining process in full here because that would take another article’s worth (and more) of information. However, if you’ve followed the steps above, you’re halfway there. You just need to organize your clues into an events list, and then have your protagonist take action throughout the story.

Let’s look at our example of Jessica and her bakery.

The basic idea is to note down the following:

1. Jessica’s conflict and goal.
2. Her external conflict.
3. An events list of what happens.
4. A short scene or chapter-by-chapter breakdown.

We already have Jessica’s conflict and goal, as well as her external conflict. Now, we need an events list that ties in with all of the above. An events list is a short breakdown of what happens over the course of the three-act story. The events are important plot points that drive the mystery forward.

• The inciting event. This is what starts off your entire mystery. Jessica’s customer drops dead after tasting her cupcake.
• The first act climax. Here, Jessica believes she’s closer than ever to solving the mystery–thus casting her back into her comfy ‘not trusting anyone zone.’ Jessica finds a clue that leads her to believe Granny is the murderer.
• The midpoint reversal. At this point, your character’s goal is flipped. Where Jessica didn’t want to trust anyone before, now she has to. Jessica snoops in a suspect’s house and gets caught. She’s arrested and has to rely on her friend to bail her out.
• The second act climax. Things get even worse. Jessica is completely stumped. She’s been reprimanded and her bakery is no longer popular because of the suspicion that she’s murdered the victim. At the end of this period of sadness, Jessica will discover or connect two clues together that she hadn’t before. Now, she really knows who did it.
• Climax. Here comes the building action and climax of the plot as Jessica faces off against the real murderer.

There’s a denouement–a resolution–as well, where Jessica and her friends celebrate their victory. Jessica will have resolved her conflict. She now loves the town and its people, and trusts her friend. Her bakery is also doing fine again.

After deciding on your events, you’ll pepper them with your clues and find unique ways to solve the mystery and tie the subplots into it.

Bonus Step 6: Mystery Don'ts

Don’t fall into the trap of relying on easy fixes in mystery stories. The readers in this genre are voracious, and they enjoy being challenged. They want you to keep them guessing until the end.

Here are a few mystery don’ts to bear in mind when writing your story.

• Don’t make it too obvious. Readers don’t want to figure out who did it in the first few chapters. They’ll stop reading the book.
• Don’t bore your reader. Don’t use too many unnecessary details or backstory elements that don’t matter. Intrigue is the key. Less is more.
• Don’t provide too much information. You want to pepper in those clues, not have two per chapter — otherwise you’ll overwhelm your reader with information, some of which doesn’t pertain to the murder mystery.
• Don’t provide too little information. You don’t want your reader to feel cheated. Give them enough clues to try to work out the mystery by themselves, but be clever about it. You don’t actually want them to solve it before you do.
• Don’t murder someone too late. Murder mysteries need to have a dead body somewhere near the beginning of the story. It doesn’t have to be in the first chapter, but you’ll need it somewhere close to the front of the book. Foreshadowing is your friend.

Conclusion: How to Write a Mystery

Follow these steps, and you’re on your way to crafting a mystery that will keep readers turning pages. Ultimately, you’ll need to read mysteries to write them–there are loads of books out there in your genre that will give you an idea of how to go about crafting the mystery element of the story. Have fun!