Austin, a neatly dressed screenwriter, house-sits for his mother in southern California while working on a screenplay. His brother, Lee, a scruffy drunk, arrives to the house and pesters Austin. Lee is not there for house-sitting, however, but for stealing. Lee's only interest at first is to rob the houses in his mother's neighborhood of household appliances. Though Austin protests, there is not much he can do to stop his brother. Austin simply requests that Lee be out of the house when a movie producer comes to visit later in the day.
While the producer, Saul Kimmer, is still in the kitchen with Austin, Lee returns, carrying a stolen television set. Rather than leave, Lee talks the producer into a game of golf and convinces him to take a look at the outline of a story Lee has been thinking about. That night, Austin helps his brother type out a ridiculous scenario involving two men chasing each other through "Tornado Country." The brothers stay up late into the night working on the outline for Saul Kimmer.
The next day, after the golf game, Lee comes home in high spirits. As part of a gamble Lee has struck with Saul on the golf course, Saul has agreed to produce Lee's project and drop Austin's. To add insult to injury, Saul wants Austin to write the screenplay for Lee's ridiculous western. Austin initially does not believe the strange turn of events, but Saul comes to the house and explains the situation. Lee's scenario is hot, while Austin's scenario is old and tired.
That night Austin gets horribly drunk while Lee tries to type out the screenplay to accompany his movie idea. The two brothers discuss the fact that Saul seems to think the two of them are the same person. Austin mocks Lee for not being able to write a screenplay, while Lee bets Austin that he could not even steal a toaster.
As the action of the play continues the brothers gradually begin to transform into one another. This transformation is marked by extensive talk about their father, who has run away from his life in the suburbs and now lives out in the desert. Though his life has been domestic and respectable up to this point, Austin now begins to feel the pull of the desert.
Chaos descends upon the kitchen: the next morning finds Austin polishing thirty toasters he has stolen from neighborhood houses overnight and Lee smashing the typewriter with Saul's golf club. Austin expresses a great need to get away from the suburbs and to live in the desert. He begs Lee to take him to the desert. Lee agrees, but only on the condition that Austin help him write the screenplay. The brothers begin to write in earnest. Lee stalks around the kitchen and Austin scribbles furiously at a pad. They are both incredibly drunk.
Without warning, Mom arrives home early from her trip to Alaska. She sees her kitchen ruined and all her houseplants dead. The brothers, not sure what to do, apologize about the mess and ask Mom about her trip. She says she came home early because she wanted to see her houseplants again and because Picasso was supposed to be coming to town. Austin changes the subject, announcing that the brothers are going to go to the desert. Lee, however, says that is not the case. Lee tries to go but Austin strangles him with a telephone cord. Mom has had enough and leaves for a motel. When Austin thinks he has killed Lee he begins to go. Lee, however, jumps up quickly and blocks his brother's exit.