Approaching the writing of a series is a bit like marriage. Are you in it for the long haul or are you more into serial monogamy?
Of course, no one really goes into marriage thinking like that, and few writers have the luxury of deciding to keep a series going into double digits. I’ve been lucky. I’m currently fussing around with number fourteen. At least that has let me think a bit about the pluses and minuses of series, especially long ones.
For a writer of historical mysteries, deciding on the framework of the series is a benefit. I picked a period with enough interesting events going on to use as inspiration to drive my mysteries as well as show how current events affect the “little people”. This also meant that my characters must age and evolve. As a reader, I love that because I form a relationship with characters I like—or love to hate. The bonding may begin as a simple matter of like or dislike, but it becomes far more complex as friendships and good marriages do. I care. I enjoy. I get disappointed or even angry at characters I like. I’m surprised when I find a disliked character does something I applaud. Eventually, I may even appreciate why I was angry and why I was pleasantly surprised. A long series is like a long life. It may be read and enjoyed for the ride, but it is best appreciated when seen as a whole. All that is a benefit of a long series.
Now the problems. Boredom is one. That is often a pacing issue for a writer. Did I go too fast in character development? The other cause is picking a character with little potential for growth. Is the voice or person only fresh and interesting for a few books, not twenty? One solution, even if you have a complex and fascinating main character, is to people your books with interesting secondaries who can pop in to delight the reader with some significant change in their lives. Your main characters get a breather. Reader is happy.
Another problem is the reverse side of a benefit. Your characters age. With medieval historicals, I have to remember normal life spans, but, as a writer, I’m allowed to give my characters longevity—even the cat—but someone is bound to die. Who? Why? I’m not a fan of doing in a major character, but the secondaries are fair game. Even here, the death of any character must be logical, not at all capricious, and serve a vital purpose in the plot. The reader may grieve but also agree, however begrudgingly. One way to ease reader pain is to introduce new characters to replace the eventually-to-be axed ones. Readers get invested in new one too. It helps to have a village.
Finally (this is a blog!), there is the problem of the dropped series, despite all the plans made for its longevity, and finding no one to pick it up. Author decision time. Writers must eat and feed the cat/dog/fish. Selling a new series is the logical thing to do. But what about continuing the old series as an independently published thing? That’s a lot of work but consider the amount of time already put into the development of that dropped series. I know what fans would prefer. As an example, I still miss Isaac of Girona.
Just a thought, but it isn’t just a series that has benefits and burdens. It’s writing. Welcome to the craft!