One of the challenges for authors, especially those who writ long-running crime fiction series, is how to keep those series fresh and interesting enough for readers to keep coming back. After all, there are only so many credible motives for murder, and only so many credible main plots. One thing authors do to keep a series strong over the long run is to introduce a variety of different characters. Of course, this can be tricky, because a ‘cast of thousands’ in a series can be confusing and even annoying for the reader. But having characters come and go over time can add to a series’ interest.

For example, Evan Hunter, who wrote as Ed McBain, created the long-running 87^th Precinct series. Some of these novels are arguably better than others are, but the series lasted for fifty-five novels. One of the reasons for this may be the way in which some of the characters moved in and out of the series. The main characters – such as Steve Carella – are stable presences in the novels. But as happens in real life, some of the other police characters come and go as the series moves on. Other characters also move in and out of the series as story arcs are introduced and then resolved. That, plus the fact that these police investigate all sorts of crime in a large city, helps the series to stay interesting.

A similar thing might be said of Michael Connelly’s Harry Bosch series. For much of the series, Bosch is connected to the LAPD. But as the series goes on, he works in different LAPD departments and precincts. And, since Los Angeles is a large city, that makes for lots of different placements. For a time he’s a private investigator, too. All of this means that he encounters a wide variety of other characters. Some remain parts of the series throughout, but many move in and out of the series. Others are parts of story arcs, but then return later. All of this helps keep interest in the series. That’s to say nothing of the fact that Bosch is partnered with different detectives as the series goes on. So, we get to learn about those characters, too, and they add to the quality of the series. This is realistic, too, as you’d expect a police officer in a large city to have different police partners and different postings throughout a long career.

Peter Corris’ Cliff Hardy isn’t a police detective. He’s a Sydney-based private investigator. Corris wrote forty-two Hardy novels between 1980 and 2016, and although some are better than others, they’ve all found welcoming audiences. Of course in a long series like this, it’s important to create credible plots, but Corris also wove several different story arcs and characters throughout the series. The meant that Hardy worked with and interacted with a lot of people as the series went on, and readers got to know some of those characters. That’s part of the reason the series didn’t die out after just a few novels. And it makes sense if you think about it. Private detectives meet a wide variety of clients as they work their cases. They also meet plenty of witnesses, to say nothing of members of the police force. All of this means a series that allows for characters to come and go, so the series stays interesting.

There are twenty-eight novels in Ian Rankin’s John Rebus series. Beginning with Knots and Crosses, the series has seen Rebus through many investigations, some of them in parallel with other investigations. Rebus has worked with several different police detectives, too, although there is a core of people who appear in many of the novels. He’s also been transferred to a few different places and contexts, which means he’s encountered other characters who’ve been involved in his cases. The flexibility of this series, which allows characters to come and go as the story requires, has meant the novels offer variety as the series goes on.

And then there’s Martha Grimes’ Inspector (later Superintendent) Richard Jury novels. Over the course of twenty-five novels plus one omnibus, Jury has mostly solved cases with his friend Melrose Plant. Still, as the series has gone on, Jury has worked with a variety of other police officers, and with a variety of different characters who’ve been a part of his investigations. There’ve been several story arcs, too, in which different characters move in and out of the series. Since Jury is part of Scotland Yard (rather than being a police detective in one particular place), he’s also done a bit of travel and met characters in different places. All of this flexibility has meant that the series stayed interesting to readers. I know exactly what you mean, fans of Deborah Crombie’s Kincaid/James series!

And that’s the thing about long-running series. A lot goes into a series’ success, of course. But part of it is arguably that the series is flexible enough for the main characters to work with a variety of other characters who move in and out of the series. This lets readers get to know new characters, follow new plot lines and story arcs, and see how the main characters develop as they work with other characters. Which long-running series have you enjoyed?

*NOTE: The title of this post is a line from The Beatles’ In My Life.