It is the end of November, and Tarrou and Dr. Rieux go together to visit the asthma patient. After listening to the patient's odd talk for a while, Rieux and Tarrou go to a terrace above the old man's apartment and sit for a talk. On the terrace, Tarrou tells the long story of how he developed the beliefs he has today. Tarrou tells of his mother, who was a quiet and self-effacing woman and his father, a nice man who had a hobby of memorizing all of the times in the railway directory. His father was a prosecuting attorney, and when Tarrou was seventeen, his father invited him to watch him in court. The experience, in which Tarrou watched his father argue for the death of an "owlish" looking criminal, shocked Tarrou, and one day, a year later, he left his parents' home. He became an agitator, an opponent of a social order based on the death penalty. He has seen executions, and is horrified by them, and he feels that the whole world is set-off if this sort of killing is allowed:
"... we can't stir a finger in this world without the risk of bringing death to somebody. Yes, I've been ashamed ever since; I have realized that we all have plague, and I have lost my peace." Part 4, pg. 252
Tarrou's explanation shows another possible philosophy, which sees human goodness as a matter of choice:
"What's natural is the microbe. All the rest--heath, integrity, purity (if you like)--is a product of the human will, of a vigilance that must never falter. The good man, the man who infects hardly anyone, is the man who has the fewest lapses of attention." Part 4, page 253
He also says that human troubles come from the failure to use "plain, clear-cut language," and claims that he's interested in knowing how to become a saint, whether it's possible without believing in God. After this discussion, Rieux and Tarrou, closer friends now, forget the plague for a moment by walking to the pier and taking a swim together in the sea.
As December passes, Dr. Rieux has no more time for leisurely swims. He is surprised one day when M. Othon, who has just been released from quarantine camp, tells him that he wants to return to that same camp to volunteer his services. Something seems to have softened in Othon, who says that working at the camp will make him feel less separated from his son Jacques, the little boy whose dramatic death Rieux and the others witnessed.
Oran is feeling decidedly un-festive as Christmas approaches, and Joseph Grand is particularly affected by the sadness. His despair one day leads him to faint, and it appears that he may have finally been infected with the plague. Grand is headed toward obvious death when he suddenly recovers in a way so dramatic, the narrator refers to it as a "resurrection." Unfortunately, thinking he was going to die, he had Rieux burn his manuscript. No matter, he says, he has it all memorized anyway. About the same time, a girl afflicted with the plague has a miraculous recovery. When Tarrou and Rieux visit the old asthma patient, he points out another good sign--the rats, which haven't been seen dead or alive since April, have begun scampering around the city again.
