Three cold cases form the basis for this novel. The cases and their roots in the past are laid out in the beginning, and then in the present a private-eye named Jackson Brodie is hired to look into them. Brodie, a former police inspector, has a number of problems of his own. His wife has left him and married another man, and he's started smoking again. His cases aren't very interesting. For example, one of them involves looking for an old woman's cats. Then the three cold cases come into his life, and things perk up considerably for him.
As he begins his investigations, the lives of the principals in the cases intersect occasionally, but only coincidentally. What really interests Atkinson, it seems, is the lives of all the characters. On rara-avis, the hard-boiled list, a couple of people are discussing one of Elmore Leonard's "rules," the one about leaving out "the part that readers tend to skip" -- detailed descriptions of weather, place, things, characters, and so on. Atkinson doesn't follow this rule. In fact, most of the book is made up of those things.
There's another rule that every writer or would-be writer has heard a million times: "show, don't tell." Atkinson flouts that one, too. Probably 80% of this book is telling. And I don't see a thing wrong with that. When did the "show, don't tell" rule come along, anyway? With Hammett and Hemingway? Case Histories is a throwback to a different kind of writing, and obviously a lot of people like it. I generally prefer leaner stuff, but now and then something like Case Histories is kind of fun.
My main problem with the intertwined stories is that I knew almost from the beginning where two of them were going. There was no way to know about the third because the information wasn't there. I also knew just about exactly what was going on with the Cat Lady and how that tale would turn out. I didn't really mind. Sometimes the trip is more important than the destination. The next time you want a change of pace from the lean and mean (if you ever do), you might give Case Histories a try.