I saw the movie "The Firm" years ago and, unusually for me, the story was so good that it stuck in my mind. So, I went into reading the book with many of the details of the story still clear to me - I could even picture the scenes in the movie. As with other films I've seen that have been made of Grisham's books, the moviemakers have stayed very close to the book - a little less with this one, but you won't be terribly unhappy with the places where they've taken liberties. I've already given my opinion away, really, any movie that I remember well for more than a year has to be good. In this case, the plot surprises and its complexity keep you fascinated. Grisham is such a good writer that even having seen the movie, you don't mind seeing the plot unfold again. It's not Tom Cruise, but then the casting was excellent! Do read the book with or without him in mind!