Keep in mind that this is a play. Plays are meant to be performed, not read.
That allowed, if you can visualize the performance as you read, you're in for a treat as you read this book. N. Richard Nash's "The Rainmaker" is the story of a family, particularly the spinsterish Lizzie Curry, and the struggle between inspiring dreams and crushing reality. The characters aren't thinly drawn as much as they are simply certain types: the cynical realist, the hopeless idealist, the withdrawn and bitter older sister, and the good-natured father holding the family together.
The year is unclear, but the play probably occurs in the 1950s, when it was written. Lizzie is growing older, and her prospects of marriage are dimming. She lives with her father and two brothers, her misery growing until a razzle-dazzle con man going by the name Bill Starbuck arrives, claiming he has the power to make it rain.
What Starbuck does have, whether or not he can end a crippling drought, is a gift to inspire and to bring healing to the Curry family as they face the audacious fire of his personality. Lizzies younger brother Jim discovers his value and potential; her older brother Noah is revealed for the negative and demeaning personality he is, and Lizzie discovers not only that she is worth loving, but that she is worth contending for.
And Starbuck? When it starts to rain, he realizes that his dreams can bring a miracle, even if its just this once.