Since winning the Pulitzer for his Glengarry Glen Ross, playwright David Mamet has written only one original, full-length play, Speed-the-Plow--yet he has written nearly ten original screenplays. His movement in this direction is both surprising and, ironically, inevitable. Studied here are Mamets screenplays (such as The Postman Always Rings Twice and Were No Angels), the influence of film on his recent plays (The Shawl and Speed-the-Plow), his theory of directing refined from his "writerly" principles of montage storytelling, and the reciprocal impact of his films and plays are discussed. Particular emphasis is placed on the author-director relationship in House of Games and Things Change. A complete filmography includes his 1992 work on the film version of Glengarry Glen Ross and Hoffa.