Dixie City Jam by James Lee Burke, Orion $60 WITH a dozen previous novels on the shelves, James Lee Burke has developed into a considerable craftsman of thrillers. Here, once again, his southern Louisiana detective Dave Robicheaux is the hero. He is involved in a highly-complex tale, the ostensible centrepiece of which is a sunken World War II U-boat. Apparently, U-boats used to lurk off the Louisiana coast to sink oil tankers. The trouble is that the author gives the impression of not being terribly interested in the submarine or its mystery cargo (although it comes in handy for a spectacular denouement). He is much more engrossed writing about Louisiana characters and the rise of the neo-Nazis, who are the villains of the piece. The dialogue rings true to an admittedly foreign ear and the locations he sets his characters in are real. The author also has a nice way with throwaway lines which appeal to my louche sense of humour. But Burke is badly served by his publishers who have printed the book in a tedious, tiny typeface, presumably in order to get all the words into less than 400 pages.