When Dr. Rieux urges the head of the medical association, Dr. Richard, to order any new cases of the disease into isolation wards, Dr. Richard insists that the Prefect must issue the order. A spate of rainy weather produces a "moody listlessness" in the population with the exception of Dr. Rieux's asthma patient who welcomes it as a curative for his asthma. Dr. Rieux and Grand meet with the police inspector for the inquiry into Cottard's attempted suicide. Grand suffers intense anxiety over his choice of words when giving his deposition. The inspector chastises Cottard for disturbing other people's peace.
Dr. Rieux lances the swellings on the necks, armpits, and groins of the victims of the disease, releasing a thick, bloody pus. Most of the cases are fatal. The newspapers that made such a fuss over the rats are strangely silent regarding the disease. Dr. Rieux and his colleague, Castel, speculate that the disease is probably the bubonic plague. Castel predicts that their colleagues and the city government will try to deny the obvious. Despite periodic outbreaks of the plague, people tend to hold the view that it has disappeared in "temperate climates."
Dr. Rieux notes that wars and plagues have always existed in human populations, yet people are always surprised when they become victims of one or the other. Even though he has personally seen several fatal cases, the events seem unreal even to him. As he recalls vivid, horrifying historical accounts of plague epidemics, Dr. Rieux braces himself for the possibility of another one.
Grand is assigned the daily task of calculating the deaths. Accompanied by Cottard, he reports to Dr. Rieux that the number of deaths is on the rise. Afterwards, he bids the doctor and Cottard goodbye because he must attend to some mysterious, important activity.
Twenty years ago when Grand accepted his job, he was promised advancement to better paying positions. However, the man who promised him the possibility of advancement has long since died, and Grand is unsure of the specifics of his promises. He has a great deal of difficulty expressing himself because he has a fanatical need to find the "right words." Therefore, he has never written a letter of protest demanding that the promises made to him be kept. Dr. Rieux intuits that Grand is trying to write a book.
Dr. Rieux wires to Paris to request plague serum. Meanwhile, his colleagues wage war against the "wait and see" attitude of the city's government. Dr. Rieux urges that immediate measures to deal with problem be taken because he fears the disease could kill off half the city. As the newspapers begin to cautiously discuss the disease, the authorities continue to drag their feet. Meanwhile, the tally of deaths continues to mount.
Grand reports that Cottard keeps acting as if he has something weighing on his conscience. The serum for the plague is long in coming, and Dr. Rieux finally realizes that he is afraid. When he checks on Cottard, Cottard seems stricken with a strange paranoia. Rieux's asthma patient speculates that the disease is an outbreak of cholera, noting that people seem nervous and jittery. Finally, Dr. Rieux demands that the Prefect take real measures to address the rising epidemic. When the serum arrives, it is adequate to deal only with the immediate cases. As spring settles on Oran, people continue to lead their lives as they always do. A sharp spike in deaths finally prompts the authorities to declare a state of plague and quarantine the town.
Just as with the rats, everyone considers it someone else's responsibility to deal with the mysterious illness in Oran. The government officials and Dr. Rieux's colleagues do not want to break with the status quo, so they waste time discussing whether the disease is definitely contagious and whether it is definitely the bubonic plague. Dr. Rieux's stance is that they should act as if the disease were the bubonic plague. He does not relish the idea of waiting for new cases to prove his suspicions. His main concern is saving as many lives as possible.
Castel understands the obstinacy of the city government and his colleagues. Even when the government posts warnings all over the city, the posters are unobtrusive. Dr. Rieux feels that the situation calls for an attitude of all or nothing. If the government does not completely implement all the measures for dealing with a possible epidemic, it is as good as doing nothing at all. Unobtrusive posters do nothing to impress the public with the potential danger of the situation. The asthma patient, as a voice of the general public, remarks that the disease is probably an outbreak of cholera, a far less serious illness. This indicates that the paltry measures taken by the city government have not been terribly effective.
Dr. Rieux realizes that human beings have too much faith in rationality to really appreciate the threat of an impending catastrophe. Wars and plagues are not rational, logical disasters. To respond to the threat of such disasters with a hysterical grip on rational, ordered thought is completely irrational given the possible scale of death and suffering that they represent.
Most people in Oran are obsessed with maintaining their "peace of mind." This obsession causes them to be indifferent to the suffering of people around them. "Peace of mind" for most people in Oran means not having to deal with the suffering of other people. They do not want their comfortable, habitual routine disturbed.
Grand and Cottard are neighbors, yet they do not really know another. Only with Cottard's attempted suicide do they become acquainted with one another. Although Grand is obsessed with learning how to communicate, he is going about it in the wrong way. He works alone on his book and his Latin, but he does not communicate with other people around him. Cottard tried to speak to him several times, but he never succeeds in communicating his fear of being arrested. Grand did not prompt him to speak, so he too lost the opportunity to break free from his shell of isolation.
Dr. Rieux thinks it is unimaginable that a city with harmless people like Grand could be subject to a deadly plague epidemic. However, there is no rational or moral meaning behind a plague epidemic. Its choice of victims is completely impartial--there is no rational or moral reason why people like Grand should or should not die from the plague.