The Long Game: Writing a Mystery Series

By Michelle Barker

While most agents and publishers want a first book to stand alone, it’s a bonus if your mystery novel (or any novel) has series potential. And if you’re self-publishing and you land on a strong concept, spinning a series out of it makes good marketing sense. 

But if you’re thinking about writing a mystery series there are several things to consider. Playing the long game requires looking ahead and planning for both a protagonist and a world that can sustain several novels. And there are some pitfalls to keep in mind.

Limited or Ongoing?

That’s your first question. In a limited series, the story arc and characters’ goals, motivations, and conflicts develop over a set number of books, usually (but not necessarily) three, and are resolved in the last book. Your decision here will likely depend on various factors: the story you’re telling, the desire to keep working on it, publisher support, and a strong fan base.

That said, you might not necessarily know how many books you’re going to write from the outset. When Alan Bradley started writing The Sweetness at the Bottom of the Pie, he thought he was dealing with a trilogy. Then his main character, Flavia, kept talking to him. He’s now at eleven books and counting.

Sue Grafton, on the other hand, knew from the start she’d be writing twenty-six novels in her alphabet series (well, she made it to twenty-five and then sadly passed away)—because that was part of the concept.

Your next decision involves whether the books will stand alone to the extent that they can be read out of order without causing confusion. Usually, an ongoing series involves novels that are episodic and resolve at the end of each book but include the same main and secondary characters throughout.

The advantage to standalones is that a reader can pick up any book and enjoy it without needing to have read all the books that came before. But in most cases, your protagonist (and possibly secondary characters) will have ongoing challenges and relationships that develop over the course of the series and are tied to things that have happened in previous books. There will be marriages, job changes, births and deaths. A skilled author can drop quick and seamless informational hints to keep readers up to speed with the overall arc, thereby gaining the best of both worlds.

How Similar? How Different?

This is another question to consider. A reader who faithfully buys all the books in a series is looking for more of the same… but not exactly the same. You’ll want to deliver on their expectations without the work becoming stale. This gets tricky. Readers expect you follow the formula but they’re also looking for change—but not too much change, or it stops being the series they signed up for.

It’s a delicate balance. To keep his novels fresh, Alan Bradley focusses on different themes—stamp collecting, traveling puppet shows—but the constant remains Flavia’s obsession with chemistry, along with her voice. Sue Grafton dug into Kinsey’s past for more story development as well as developing some of the secondary characters and various relevant social issues—but Kinsey’s personality has been consistent throughout the series.

Who Is Your Detective?

The detective’s personality might be the most important component of a mystery series. Readers love to bond with the detective and try to solve the crime alongside them (maybe even before them). While they love the puzzles, it’s the voice they’ll keep coming back for. The personality of your detective. Think of Mma Ramotswe in Alexander McCall Smith’s acclaimed mystery series: her combination of warmth and common sense wins readers over.

Before you start writing, spend some time figuring out who this person is and why they’re worth following from one case to the next. Develop their backstory and their moral code—an essential component of the detective’s character. How do they think? What is their method of solving crimes? Do they have an enduring concern or challenge beyond the immediate crime they’re trying to solve? As an example, Mma Ramotswe is the only female detective in Botswana, so she constantly comes up against toxic masculinity.

What Does Your World Look Like?

A series means you’re going to be living in this world for many years, so think carefully about where you want these books to be set and why. Alan Bradley chose the early 1950s in England which allows him to use the fallout from the war and capitalize on Flavia’s general invisibility in her world (so that she can get away with more than she might now). Sue Grafton sets her novels in the 1980s, before the advent of modern technology in crime detection, in Santa Teresa, a fictional city in California based on Santa Barbara (but without any danger of lawsuits). 

Setting is a crucial component of the mystery novel. If developed to its full potential, it can contribute to clues, alibis, red herrings, and misdirects. It can amplify tension and foil the detective (or the criminal). And of course it will provide your crime scene. So: choose wisely.

The Series Bible

One way to keep track of all the details spanning several novels is to create a series bible. This might include the physical descriptions of each character, their age, profession, backstory, relationship to other characters, their relatives, hobbies, likes and dislikes. It might also track various elements of setting.

Your series bible becomes a database for you. Each time you add a character or mention a characteristic, add it to the bible. If you do this, you’ll never be stuck searching through previous novels to remember the color of Henry’s eyes or suddenly find yourself giving him a sibling when you mentioned in Book Three that he was an only child.

Consistency isn’t the only consideration. You might also want to track things like types of crimes, killers’ motivations, red herrings, and solutions to make sure you don’t do the same thing twice.

The Passage of Time

If you’re writing a series, you’ll probably aim to put out a book a year. Will your characters age a year between each book, or will each book take place days, weeks, or months after the preceding one? This is something you’ll need to decide in advance.

Sue Grafton purposely didn’t age Kinsey Millhone that fast because she wanted her novels to take place before the advent of modern technology so that Millhone could solve crimes “the old-fashioned way.” Flavia de Luce also only ages a little at a time from book to book because a key part of her charm—and her level of curiosity—is her age. This also allows Alan Bradley to keep his historical setting consistent.

If your detective ages along with the series, you will want to consider the implications. What will happen when they hit sixty-five? What happens to their aging parents? Their children?

How to Keep Things Fresh

In a Goodreads interview, Sue Grafton said her goal was “never to write the same book twice.” Even though you’ll end each book in the series by resolving that book’s plot and having your detective solve the crime, you’ll still want to give your reader a reason to come back for more. Here are some ideas on how to accomplish that: 

• Allow for development in the main character’s life: do they go back to school? Move to a new town? Reconnect with an old friend?
• Speaking of friends, can you introduce a new character into the protagonist’s life? Maybe someone who causes trouble for them?
• Dig back into your previous novels for possible seeds that you’ve planted that can be developed into a new storyline.
• Depending on when and where your novels are set, you might look to current or historical events to introduce something new to the series.

Find the Connective Tissue

But fresh is just one thing. The series also needs connective tissue—relationships, rivalries, scars that deepen, personal mysteries that need to be solved. There are many places to find those: 

• Dig into your protagonist’s backstory for old wounds and new developments.
• Give your protagonist an ongoing challenge or relationship that can be developed over several books.
• Give your protagonist a long-term goal. Maybe they can make halting progress as the series proceeds.

The Last Word

For anyone who thinks they could never write a mystery series, let’s let Sue Grafton have the final word: “When I started [the alphabet] series, I knew nothing about police procedure, I knew nothing about private-eye procedure, I knew nothing about California criminal law or about guns or ballistics or toxicology. I had also never written a mystery before. It took me five years to write A is for Alibi because I was struggling on about five fronts, trying to pull it together and pretend I knew what I was talking about.”

It can be done. If you have a strong concept that you believe might have series potential, start studying mysteries, read as many as you can, and jump in!

Michelle Barker is an award-winning author and poet. She is the co-author of two craft books: Immersion and Emotion: The Two Pillars of Storytelling and Story Skeleton: The Classics. Her fiction, non-fiction, and poetry have appeared in literary reviews worldwide. She has published three YA novels (one fantasy and two historical fiction), a historical picture book, and a chapbook of poetry. Michelle holds a BA in English literature (UBC) and an MFA in creative writing (UBC). Many of the writers she’s worked with have gone on to win publishing contracts and honours for their work. Michelle lives and writes in Vancouver, Canada.