In the Jesse Stone novels Robert Parker is allowing himself the luxury of exploring obsession. Spenser's has only two obsessions: being a knight, and Susan Silverman. He has both of them well in hand, and part of the pleasure of reading his stories is the sense of well-being that he exudes, a thing rare in the detective genre.
Jesse Stone has his job pretty well in hand, but it's a job that way down the list from the big city homicide detective that he used to be out on the west coast. Paradise isn't far from Spenser's Boston. In fact, a few of the minor characters from that universe spill over into this one.
Jesse needs to have his job, because the rest of his life is a but of a mess. To start out with, he's an alcoholic; spends time brooding about booze, trying to convince himself that he can control it, deciding not to, as if that make a difference. The series isn't awash in liquor, but Jesse has a lot of hangovers and a lot of regrets.
One of the regrets is that he blew out his pitching arm before he could get a shot at the majors. Being a cop is second best for him, though he does like the sense of order that goes with the job, he does like helping people, and he is fairly good at it.
Another of the regrets is that his marriage didn't work. He and Jenn are still in love with each other (co-dependent might be a better word) but they aren't married any more, and it didn't make Jesse's life any easier when she took a media job in Paradise. Jesse has a lot of opportunities to move on with several other women, but he tends to start out a relationship by explaining that he's still in love with Jenn, and that he will be with her if they can ever work something out.
All of that has something to do with the booze but, as Dix (the counsellor he starts seeing in this book) says, Jesse was always an alcoholic-in-waiting, even before the marriage problem.
As you might expect with Parker, all of those relationship things are the real story. There is a murder to be solved, but it's primarily a thread on which to string the rest of the beads. The dead girl had a high school rep as the proverbial good time had by all, and she apparently had moved into what folks like to call the sex trade these days. That she was underage was just part of the turn-on for a certain type of customer.
It takes the Paradise detachment quite a while just to find out who Billie is, and then longer to get her parents to admit that she ever existed. Billie, you see, is a runaway - almost a throwaway as this story develops. Her sisters aren't happy at home either, but the oldest one coped until she could get away to college, and the younger one lives two lives.
Off to one side of this investigation there is the case of a disturbed couple. The wife has been on the receiving end for years, but keeps making excuses. When the police finally persuade her she's in danger, she finally takes stock of the situation. When it's all over, Jesse really isn't sure if he handled the case correctly. The best thing he can say about it is that it's night he decided not to drink and actually didn't.
I'm not how long a run the Stone series can have. I'd be tempted to say that the struggling alcoholic subplot could age quickly, but then James Lee Burke and Lawrence Block have both managed to get good mileage out of it, so it could go on for a while. So far it's not boring. The Parker style is in evidence, but this is clearly NOT Spenser. The writer is experimenting more than he has in some years, and the results continue to be interesting.