The play which earned Sam Shepard the Pulitzer Prize in 1979. It is a perfect example of American Gothic, which is quite similar, but not as geographically limited, to Southern Gothic.

It deals with a decaying family, terrible secrets, religion, murder, incest, and the restoration of fertility and order. Instead of giving you a full synopsis of the play, I suggest going and seeing it. However, I will point out that it is important in that it is:
a.) arguably Shepard's best and best-known play
b.) a perfect example of Shepard's use of the themes myth in modern life