First off all, you should always read the book first. I think it is a pretty good adaption. John Grisham fans should not be disappointed by the choice of actors for the parts in the book. Especially Tommy Lee Jones, a personal favorite, plays his part well, and his scenes with Sarandon are the best part of the film. They keep testing each other and have some verbal clashes but in the end you can see Jones' character isn't as bad as he seems and he clearly respects Sarandon's efforts. Only negative comment for this movie is that it never seems to reach the suspense it is aiming for and so it becomes good entertainment for one evening but forgettable soon after.
Review of The Client
