The Stranger is a novel. The protagonist is indifferent to reality because he finds it absurd and incomprehensible. Technological progress has deprived him of participation in collective decisions and has turned him into... "foreigner" within what should be his own environment.
The protagonist, Mr. Meursault, commits an absurd crime and, despite feeling innocent, never protests his execution nor shows any feeling of injustice, remorse, or pity. Passivity and skepticism toward everything and everyone permeate the protagonist's behavior: an absurd sense of existence and even of death itself.