"The Stranger" by Albert Campus touches upon many heavy elements... but not in the way you expect. Although it touches upon the aspects of death and love, it also deals with a hidden philosophy similar to that of nihilism.
The story follows the short life events of Meursault, a Frenchman whose carelessness for his actions eventually ends him in jail and dependent on a jury of people to judge the ethicality of his decision and the punishment that he deserves. He eventually gets the death penalty and all throughout he is nonchalant and almost apathetic towards his situation. He finally snaps when the prison sends a priest to him to absolve him of his sins and to cajole him in confessing to the lord.
With this final straw, Meursault takes out all his anger on a system of forced belief into something so irrational and out of control. He angrily questions why he was evaluated as a bad person because he didn't cry at his mother's funeral or because he chose to not believe God. Especially in the legal field where everyone tried to make sense of his actions, he protests that this world is made of people who struggle to rationalize all the chaotic and unexplainable phenomena around them.
Albert Campus is quite famous, from what I've heard, for pioneering or at least revolutionizing the idea of absurdism. One important thing to note is that this is not to be confused with nihilism and existentialism. Nihilism is the idea of believing life has no meaning and that such concepts that try to bring meaning like religion are false ideologies. Furthermore, any meaning that we try to build for ourselves is false and fabricated.
Pretty miserable, if you ask me.
Existentialism believes that people can make their own meaning but holds the same amount of truth as religion. Existentialism can accept or reject religion. Absurdism, is usually the philosophy in between. It explains that while religion and ideologies we build in our minds can be completely fabricated and fictitious, there is a function in these beliefs. These beliefs are what allow us to move on from the chaos in our lives and continue on with living without the fear of an irrational and unpredictable universe.