Many—not all but many—movies have two genres. The first tells the story of the main plot line: the heist, the hunt for the spy, the fight to save the farm, the escape from the haunted house. Those are all the high-stress moments of the story, building tension to the finale. When the marketers cut a trailer, this is the genre they focus on.

The second genre tells a story in the down moments of the plot, when the tension of the main plot is allowed to ease and reset so it can be ramped up again. Traditionally, these would be romantic plots, but sometimes it’s a coming of age story.

TV does something similar. For example, Elementary was a mystery show that had, for its second, much smaller secondary plot, a little drama that played out within the main cast. Most focused on the growing friendship between Sherlock and Joan, but some were about Joan’s family, or Sherlock’s, or their circle of friends.

And since it’s an episodic show, the main-plot mysteries were one and done but the little dramas stacked one on top of the other, building over the long term to something wonderful.

Honestly, in TV it’s those tiny dramas, building one upon the other, that keep me coming back episode after episode. The Mystery of the Week keeps me entertained. The slowly changing relationships between the main characters makes me binge a whole season to Find Out What Happened.

Another example: for years, I was faithfully picking up Sue Grafton’s alphabet novels, one after another, because a) the private eye plots for each book were solid as hell, and b), the main character, Kinsey Milhone, discovered that she had a huge extended family that she knew nothing about, and the subplots of each book showed her inching closer to the family she never knew she had and wasn’t sure she wanted.

I really wanted to know what happened between Kinsey and her estranged family. I could find a solid mystery in any number of books, but the family drama is what kept me coming back.

Then the subplot suddenly shifted into a romantic plot featuring a good-looking homicide detective who used to be a hairdresser(!) which meant he could fix Kinsey’s famously terrible self-inflicted haircuts. I was so annoyed that I dropped the series immediately. I’d been coming back for the reconciliation with her family. The sexy hairdresser/homicide detective left me clammy.

One of the reasons I never watched House was that, while the main plots were interesting enough, I didn’t like watching the character dramas play out. It just felt so squicky. In fact, there are a lot of shows that I ditch after a few seasons because I feel absolutely done with the kind of subplot dramas the show puts its characters through.

Anyway, the reason all this has bubbled to the surface is the British show Miss Scarlet and the Duke. Brief description: Eliza Scarlet is a Victorian-era daughter of a police inspector and private investigator who is obsessed with being a private investigator herself, and of course she’s brilliant. “The Duke” is the nickname of a Chief Inspector of Scotland Yard, William Wellington. They’re childhood friends who love each other. The dynamic on the show is that he helps support her struggling business while she solves his most difficult cases.

Did I mention that they love each other? In season one they’re friends trying to accept their mutual attraction. Season two has them in a romantic relationship while Eliza’s dedication to her work keeps causing problems for William. Season three has them trying to be friends post-breakup, even though William begins dating Eliza’s childhood bully.

Then season four hit the library on disc and I was 100 percent ready for it. Three ended with the (now more adult and sensible bully) dumping William because he can’t admit that he’s still in love with Eliza. So four ought to be the season where they try again and actually make it work, right?

Well, no. Instead, William takes a posting in New York City. He tells Eliza that he loves her but that they need time apart.

And the next thing I discover is that season five will be called simply “Miss Scarlet” because Stuart Martin, the actor who played “the Duke”, is leaving the show.

Which I get. It can’t be fun to be the cop who scolds the main character for all the cool and fun ways they break the rules. Taraji P. Henson pulled the ripcord on Person of Interest because her role had changed and she’d become bored. I’m sure Martin believes there are better ways to spend the sexy leading man years of his life.

But I’m not sure I’m interested in a show without that subplot. The structure of each episode was such that each multi-season-long subplot was woven tightly into the execution of the mystery of the week. What, exactly, is supposed to fit into that space?

I have no idea, but it’s like imagining a Twenty Palace novel without Annalise. It just doesn’t make sense to me.

I mean, I’ll give season five a try, but I have to admit that I’m feeling a little cheated. If he’s leaving the show, I’m glad they didn’t kill off the character, because that would have sucked. I’m still disappointed in the unresolved ending of this four-year storyline, though.

(I should write shorter posts)