"Leonard is a very good writer he manages to get into his characters and build a believable situation." "The writing is tough and realistic. The approach does owe something to George V. Higgins, but Leonard is nobody's follower, and he has a style of his own.
To build suspense. Plays are not interesting without conflict. In this case the conflict surround John Proctor, the tragic hero, we would not be interested in Puritan drama.