I decided to read all of the Adam Daigliesh mysteries in one fell swoop and am glad I did. First, they are classic British mysteries all well-deserving of the respect P.D. James has earned for them and all are a good read. However, what is interesting is to watch the author develop her style from the early ones to the later ones. And, in fact, A Shroud for a Nightingale and The Black Tower (the fourth and fifth in the series) is where she crosses the divide. The later books have much more character development -- both for the players and the detectives -- make Dalgleish more rounded and are generally much more than a good mystery yarn -- they're fine novels that happen to be mysteries. The first three books (Cover Her Face, A Mind to Murder, Unnatural Causes) are just that much more simplistic. But read any or all -- she's a great writer and they are definitely worth the time.