I did a little on the current book and a lot on the fourth book. I like cozy series to have a real character arc. But I have to admit, it is a tricky thing. Cozies have to have a certain consistency. The point of the series is that you can count on it. Columbo never changes, nor does Perry Mason, or Miss Marple.
With a hard-boiled or police procedural, it's easier to have an arc, because the world is already disrupted. It's normal for characters to have their lives thrown for a complete loop that changes everything. Especially with police procedurals, the lives of the characters can become a real pot-boiler or soap opera, while the job provides a steady beat for the series.
And romantic plotlines provide a lot of opportunities for multibook arcs too - but they have the problem of peaking. For instance, Charlotte MacLeod's series about Sarah Kelling and Max Bittersohn had a bang up beginning. The relationship is utterly unrequited for the first book, and it takes a couple of books for it to get up and running, and then they get married and.... not much happens after that.
Part of the problem, though, was that the first book was so poignant. It had humor, but it wasn't a light read. The later books got lighter and lighter, until I stopped reading when in a later book Sarah stumbles across a body and basically says "oh bother! Not another one!" That might be okay in a series that started with that tone, but this series promised something different. The arc lost it's pizzazz.
Anne Perry did a better job later with Charlotte and Thomas Pitt (which isn't really a "cozy" but a darker domestic mystery series, if you want to be technical), except that she cheated at the beginning. I was SOOOO mad at her. I had started reading the series a couple of books into it. When I finally got my hands on the first two books, I found that she had completely skipped the interesting part.
In the first book, these two interesting characters meet and throw some sparks, but there is no romance until the last page. That promises so very much when you have a Victorian mystery with characters from completely different background and social class. But no, we don't get to see how that whole courtship thing worked out at all. At the beginning of book two, they are safely married. But even though she skipped that romantic character arc, the series persisted well because she built it on the second book. Their marriage is the rock, and everything else in their lives might grow and change and challenge them. So it worked. Even if it did piss me off.
The thing is to find a way to combine the character growth arc with the steady bedrock of the series that is there from the start. We never saw the romance of Mr. and Mrs. North (although in some ways the series is a "romance" between this charming couple and the policeman who befriends them) but we could always count on the tone that brought ditzy brilliance together with steady police work.
So you find the bedrock, and let everything else build on it. And for me, a part of finding the bedrock is writing more than one book at a time.
Running Total: 23861
We learn significantly more about George's background when his parents decide to show up at the Marquette-Rosewalt family Thanksgiving.