False Tongues by Kate Charles is not the kind of novel I usually read, but I enjoyed it. And it's helping me understand the kind of book I want to write.
Callie, the principal character, is a curate in the Church of England. Her boyfriend, Marco, is a police officer who supports families who are victims of crimes. Marco is assigned to a family whose teenage son has been murdered. DI Neville Stewart is assigned to find the murderer.
So Callie is not directly involved in solving the crime. Neither are her vicar and his wife, her friends from theological college who gather for a reunion, nor the principal of the college, who falls in love with a visiting priest during the reunion, but we spend a lot of time with all of them.
It's fair to say the structure of this novel is similar to that of the film, Love Actually (2003): lots of people, lots of stories, surprising connections among them. I enjoyed both that film and this book
If someone removed all the scenes and characters who do not contribute to solving the mystery, the book would probably be less than 200 pages instead of 339. I suspect the author spun out the loosely connected subplots in order to make the book as long as publishers want books to be these days.
Almost three years ago, I wrote a blog post entitled Why did books get longer?". I had just read Michael Connelly's Two Kinds of Truth, a big book divided into Part One, Part Two, and Part Three. Since each part tells a separate story, the book is really two novellas and a short story, put into one book and called "a novel."
I have read that books of 80,000 words (240 pages) sell best on Amazon, and that a book must be 100,000 words (330 pages) in order to be commercial. Some authors make a mystery longer by making the plot more complicated to solve; some do it by including more description of scenery; some bundle more stories together.