Meursault describes his early days in prison. He at first does not feel himself to be in prison, instead feeling like he's "sort of waiting for something to happen." From his cell he can see the sea. Marie visits and the two of them sit in the row along with other prisoners and visitors, shouting across a wide barrier between them. Marie tells him "to have hope," tells him he'll be freed and they'll be married. Meursault thinks Marie looks beautiful and wants "to make the most of [her] being there" but is also distracted by the other prisoner-visitor interactions and sickened by the noise.
Meursault's first impression of prison – like "waiting for something to happen" – is grimly accurate. He is waiting for a trial, for a sentence, and, eventually, for death. Marie tries to bolster their relationship with encouragements. Meursault can't help but be bothered by the physical distractions.
Marie waits at the bars even when Meursault has to walk back to his cell. Soon after, she writes to say she isn't allowed to visit anymore because she isn't Meursault's wife. Meursault marks this letter as the point at which prison truly started for him.
Prison rules show that the law organizes human relationships within a hierarchy: unmarried romantic relationships are less important than marriages. The moment Meursault is forced to comply with this hierarchy—which is meaningless to him because marriage is meaningless to him--marks the moment prison truly starts for him because now he is being restricted by society's belief structures.
Meursault describes acclimating to prison. At first "the hardest thing was that my thoughts were still those of a free man." He wants to go to the beach, to have sex. Meursault befriends the head guard who explains the whole point of prison is to take away men's freedom, that that is the punishment. Meursault realizes, "I'd never thought about that," and agrees. He eventually realizes that not getting to have cigarettes is "part of the punishment" as well, though it "wasn't a punishment anymore" after he gets used to not smoking.
Though Meursault is acutely aware of the physical experience of deprivation in prison, he is, as usual, focused on concrete particulars without considering the potential meaning behind them. The head guard articulates the meaning and purpose of prison from the perspective of society at large.
After the first few months, Meursault's "only thoughts were those of a prisoner." He thinks he would "have gotten used to it" if he'd been confined inside the trunk of a dead tree. He cites it as "one of Maman's ideas…after a while you could get used to anything." Meursault looks forward to his lawyer's neckties just as, before prison, he looked forward to holding Marie. "Killing time," he spends hours remembering every object, color, crack, detail in his apartment in Algiers. He "realized then that a man who had lived only one day could easily live for a hundred years in prison" because he would have enough memories to recount to keep from getting bored. He learns to sleep for three-quarters of the day.
From Meursault's perspective, everything is interchangeable and nothing has intrinsic value – his lawyer's neckties can become as pleasurable as holding Marie. His memory practice leads him to appreciate the full richness of physical experience, realizing that even one day's worth of memory would be intricate and vivid enough to fill a century's worth of memories. The grandeur of this vision and the strength of Meursault's faith in physical experience present an alternative to religion: one can focus on and be guided by remembering worldly life, not imagining an afterlife.
Meursault repeatedly reads an article he found describing a man who got rich and returns to his village to surprise his mother and sister after 25 years. He takes a room in their hotel anonymously, as a joke. Not recognizing him, his mother and sister bludgeon him to death to rob him in the night. When they find out what they've done, they kill themselves. Meursault reflects about the story: "on the one hand it wasn't very likely. On the other, it was perfectly natural." He thinks the man deserved his death as "you should never play games."
The article's story functions as a grotesque parable of life's meaninglessness. Another striking use of the word "natural" – by "natural" here, Meursault may mean "understandable" or he may mean "just," if he really believes "the man deserved his death."
Time loses meaning for Meursault and the days "lost their names. Only the words 'yesterday' and 'tomorrow' still had any meaning." When told he's been in prison for five months, he "believed it, but…didn't understand it." That day, he looks at his reflection, which stays "serious" even when he tries to smile, when he feels he's smiling. At that moment, he realizes that he's talking out loud to himself and realizes, in fact, that he's been narrating his thoughts out loud to himself ever since he got to prison. He remembers "what the nurse at Maman's funeral said. No, there was no way out."
Time never had much meaning for Meursault but it has even less now. The mirror scene inverts Meursault's internal thoughts and external appearance: his facial expression, which should be plainly visible, is invisible. But his thoughts, which should be inaudible inside his mind, are audible. The nurse's words return as a sinister, cryptic warning, seeming to suggest, here, that there is no way out of mind-distorting time in prison.