In this story and in Camus' oeuvre overall we need to take into account several types of "isolation." First, there is the physical isolation of the setting, the wide open spaces of Algeria. Second, there is the mental isolation of characters such as Daru in "The Guest" and Meursault in L'Étranger. Last, there is the existential isolation of man alone in a universe where he feels himself a stranger.
Daru, in his isolated situation at the school after an unusual snowstorm, does not want to turn the Arab man over to the authorities. Perhaps he feels a kind of solidarity with the man (though the French colonials and the indigenous North Africans think of each other as the enemy) because in some sense, the Arab man has become a stranger in his own country as well, hunted down by the gendarmes. Yet the message left by the man for Daru shows that any attempt at bonding has failed. In the conflict between the French and the native Algerians, there does not seem to be any possibility of resolution and, still less, of ultimate peace and unity.
At the same time, Daru is alienated from "his own" people. He cannot sympathize with the hard liners who wish to crush their adversaries. This is a world in which there is sound and fury but no meaning except that which man, in his isolation, can hope to create for himself, as Daru tries to do by releasing the man.
First, Daru is very much physically isolated at his schoolhouse in the desert. When Balducci arrives, Daru is surprised to have any visitors, which indicates that it is a rare occurrence. In addition, the snowstorm has deterred his small number of village students from attending for four days. Daru’s only normal interactions are with his students, which also suggests his social isolation.
As a lone adult among children, Daru lives in a small room adjoining the classroom. Communicating only with children in the role as a teacher/mentor, one might infer, is socially alienating because of the age gap. Daru demonstrates his awkwardness around others in his first encounter with the two visitors. He makes a joke about “odd pupils” that falls flat, and he tries to make the visitors comfortable—even though the situation is wholly uncomfortable for everyone.
Daru’s psychological isolation is best exemplified in the following quote:
“This is the way the region was, cruel to live in, even without men—who didn't help matters either. But Daru had been born here. Everywhere else, he felt exiled.”
Daru seems to dislike his lonely existence yet bristle at the negative influence that people can have on his life. He doesn’t feel happy in the place of his birth, but he also doesn’t think he belongs anywhere. Daru sees himself as an outsider no matter where he lives, which explains why he is able to survive as a rural schoolmaster. He simultaneously wants to be left alone and wants to make a positive impact on people’s lives.
Daru suffers from alienation because he must operate in an absurd world, a world that is irrational and meaningless, and his attempts to find some order in this world bring him into conflict, thus increasing his isolation. Within the setting of the Arab uprising against the French, Daru feels that his actions regarding the prisoner will make little difference, or they will be misconstrued anyway. Added to this, Daru is part of both cultures, so he operates with a certain ambiguity as to his loyalties.
No one in this desert, neither he nor his guest, mattered. And yet, outside this desert neither of them, Daru knew, could have really lived.
When the prisoner is brought to him by the "old Corsican," Balducci tells Daru that he will not denounce the schoolteacher if he does not comply with the military orders, so Daru must make his own decision. But, although the man's "stupid crime revolted him... to hand him over was contrary to honor." Thus, it is an existential decision that Daru must make in this absurd situation. Having to do this leaves Daru isolated because he follows only his own conscience and no rules made by either culture, French or Arab.