No Exit (Huis Clos) is one of Sartre's finest plays; it is produced and studied more than any of his other dramas. The setting is Hell even though it resembles the real world around us. Three characters come together in this microcosm of Hell in a way which shows their indispensability to one another: They become inextricably involved in each other's stories, and they represent the fundamental idea of the play-namely, that other people are torture for us. The question of "the others" is integral to the works of Sartre; he describes over and over how other people can condemn us, define us, withhold love from us, murder us — in short, take the power away from us to live life as we wish.
But "the others" cannot rob us of our freedom, and this is the central notion in Sartrean existentialism. The anguish which we feel when we are confronted with the vast and meaningless universe is something which Sartre calls "nausea." To combat this "nausea," man can use his freedom — freedom of thought, choice, and action. But once man has chosen and acted upon his choice, there is no turning back: This choice stands as an imprint on his essence, on his human makeup, and it follows him for the rest of his days. In No Exit, Sartre pushes this idea to its extreme, showing how the torture of looking back on our past is a form of Hell, particularly when we fail to choose an act when the opportunity presents itself. If man is alive, he can always choose to rearrange his life, but when he dies, the lifelong events are frozen into a mold which can never be broken. This is the atmosphere in No Exit, where all three characters have died and are condemned to the unmalleable truth of their past actions. Contrary to the situation in The Flies, this play shows what happens when people do not choose properly. In The Flies, we witness the results of correct, as well as incorrect, choices.