One of the main ways Williams dramatizes fantasy's inability to overcome reality is through an exploration of the boundary between exterior and interior. The set of the play consists of the two-room Kowalski apartment and the surrounding street. Williams's use of a flexible set that allows the street to be seen at the same time as the interior of the home expresses the notion that the home is not a domestic sanctuary. The Kowalskis' apartment cannot be a self-defined world that is impermeable to greater reality. The characters leave and enter the apartment throughout the play, often bringing with them the problems they encounter in the larger environment. For example, Blanche refuses to leave her prejudices against the working class behind her at the door. The most notable instance of this effect occurs just before Stanley rapes Blanche, when the back wall of the apartment becomes transparent to show the struggles occurring on the street, foreshadowing the violation that is about to take place in the Kowalskis' home.
Though reality triumphs over fantasy in A Streetcar Named Desire, Williams suggests that fantasy is an important and useful tool. At the end of the play, Blanche's retreat into her