This is one John Grisham which chooses to be different from all the others. A general pattern that fiction writers seem to follow, and especially thriller writers, is that tend to write repeatedly on a pattern similar to the one in which they achieve success. The same has been the case with John Grisham. He generally writes thrillers using law as the subtext and backdrop, and his books are generally are easy on the reader.
This book, although based on a facet in law, is an exception, since it is exactly not a thriller. There is a deeper human story and deeper human emotion which is brought out to the surface. The theme of the book is based on insurance related frauds, and how people are conned out their savings, even when they are on the deathbed. The protagonist of the novel, a young rookie lawyer, goes through a roller coaster of human experiences in terms of pain, suffering and what the little joys of life stand for. And along with himself, Grisham through his eloquent prose takes the reader along a similar rollercoaster too.
You can also find a movie made on this novel, as you find on a host of other Grisham novels. I would like to add that this is one movie adaptation that I have liked. Generally a movie loses the essences of the book, for the constraints of time and space to represent it suffers vis-à-vis the literal medium. But this is a definite exception. So you could also watch the movie once you have read the book.