Oxford. The Thames Valley Police. Names that evoke, in mystery fans, the unforgettable characters of Morse and Lewis, and the televised “Endeavour” prequels. But this is not one of those stories.

Black River, by Joss Stirling, is a different sort of mystery altogether, in the same setting. It’s billed as the first book in a series, although the story harkens back to previous events in the main character’s life, as if the reader already knew about them. Perhaps it’s a spin-off of another series.

Our heroine and central character is Jess Bridges, a short, pretty, curvaceous young woman who has ADHD, which makes her both impulsive and (apparently) ditzy. She has recently set up as a private investigator, specializing in missing persons. Currently she’s trying to contact a teenaged girl who has moved out on her mother and in with her recently divorced stepfather.

But that inquiry gets interrupted when, inspired by a bestselling book on “wild swimming” in England, she goes skinny-dipping at one of the author’s recommended spots, only to discover the body of a murdered man in a boat. This results in her meeting Jago Jackson, the author of the book himself, who happened to be cycling in the area, and Inspector Leo George, who heads up the murder investigation. The three of them (and several others) will meet again and again, as Jess goes undercover, taking a job with a movie crew filming at an Oxford college, and the two cases start overlapping. At least in terms of location.

The plot was complex – which really isn’t a negative criticism for a mystery. It was a pretty easy read, and the writing was good. There was a touch of French farce about the whole thing, as Jess tends to land in repeated, embarrassing sexual situations. My stuffy puritanism found that a little excessive.

However, I also noted that the author made an effort to avoid foul language. I didn’t love this book, but you very well might like it better.