Trouble with really good writers is that they sometimes can get so involved with techniques and style that they tend to forget the raison d'être of the crime novel. So it is with "The Black Tower."… Mrs. James is an exceedingly good writer, and her detective, Adam Dalgliesh, is one of the more unusual ones in action today. Nevertheless, "The Black Tower" is so slow-moving that it will try the patience of most readers—and that has to be the besetting sin of a crime novel.

In "The Black Tower," Dalgliesh is recovering from a serious illness. He is on a convalescent holiday when an old friend dies. There are curious circumstances; there are poison-pen letters; there is a missing diary; and there is unfortunately almost a total lack of action for a good half of the book. It's heavy going, and one says this with some...