An unnamed narrator, who promises to reveal his identity later, states that the chronicle that follows is as objective as possible. He assures the reader that he reports only those things he witnessed himself, the eyewitness accounts he received first hand, and a written eyewitness account of the events in question.
In the Algerian city of Oran, Dr. Bernard Rieux steps out of surgery and finds a dead rat lying on the landing. In the days that follow, an increasing number of rodents stagger out into the open and die, blood spurting from their muzzles. Dr. Rieux, preoccupied by his wife's impending trip to a sanitarium, doesn't give a great deal of attention to the phenomenon at first. M. Michel, the concierge for the building where Dr. Rieux works, is convinced that the dead rats in the building have been placed there by pranksters. Dr. Rieux's elderly asthma patient declares that hunger has driven the rodents to die in the open by the hundreds. A young journalist, Raymond Rambert, calls on Dr. Rieux to discuss his current project, a report on the sanitary conditions in the Arab population. Dr. Rieux's main concern before talking with Rambert is to make sure that Rambert will report the truth about the sad state of public sanitation.
Dr. Rieux's mother comes to stay with him while his wife is away. Meanwhile, Dr. Rieux contacts Mercier, the man in charge of pest control, to suggest that sanitation measures be taken. The public begins to feel uneasy when the flood of dying rats continues to increase. The newspapers clamor for the city government to address the problem. In response, the city arranges for the daily collection and cremation of the corpses. Just as a mild hysteria begins to grip the public, the phenomenon abruptly disappears.
The same day, Dr. Rieux meets Father Paneloux, a Jesuit priest, escorting a feverish, weakened M. Michel to his home. M. Michel's neck, armpits, and groin are swelling painfully. Dr. Rieux promises to visit him later in the afternoon. Meanwhile, he receives a telephone call from a former patient, Joseph Grand, regarding an accident suffered by his neighbor, Cottard. Upon his arrival, Dr. Rieux discovers that Cottard has tried to hang himself. Cottard becomes agitated when Dr. Rieux states that he will have to submit a report about the incident to the police. Dr. Rieux visits M. Michel to find his condition worsening. M. Michel dies in an ambulance en route to the hospital.
Other victims succumb to the same illness in the days that follow. The narrator introduces the reader to Jean Tarrou, the author of the written documents mentioned earlier. Tarrou, a vacationer in Oran, keeps notebooks containing detailed reports of his observations about daily life in Oran. He records conversations regarding the appearance of the mysterious illness in the wake of the dying rats. An old man periodically comes out onto a balcony opposite Tarrou's hotel room to spit on the cats sunning themselves below. When the plague of dead rats entices the cats away, the little old man seems greatly disappointed. Tarrou writes about a family of four with a disagreeable, strict father, M. Othon, who dines every day at the hotel. The hotel manager, dismayed at the dead rats in his three-star hotel, takes no comfort in Tarrou's assurance that everyone is in the same boat. The manager snootily explains that he is bothered precisely because his hotel is now like everyone else. One of the chambermaids becomes sick with the strange illness, but the manager assures Tarrou that it probably isn't contagious. In the midst of these vignettes of daily life in Oran, Tarrou ponders philosophical matters such as how not to waste one's time.
At the end of The Plague, the narrator reveals himself as Dr. Rieux. Perhaps Dr. Rieux withholds his identity because he is concerned with maintaining his objective distance from the chronicle. Because he defines The Plague as a chronicle, one would expect a journalistic report of the facts. Considering Camus's ideas about the impossibility of reaching an objective truth, it is not possible to agree with Dr. Rieux's assessment of his own document. Furthermore, despite Dr. Rieux's claims of objectivity, his description of pre-plague Oran society is heavily laced with irony. Rieux states that the spirit of pre-plague Oran is one of empty commercialism. The lives of Oran's people are entirely circumscribed by their habits. Every day, they follow the same routines of work, movies, cafes, and shallow love affairs.
One would assume that people would take immediate action in response to a phenomenon as grotesque as the dying rats, but to do so would require a grave underestimation of the power of indifference and denial. The city government is slow to respond to the problem. Rambert's newspaper refuses to publish a full condemnation of the sanitary conditions in Oran. It is only whent the newspaper swings into ponderous motion and begins clamoring for actionfor action that the city government arranges for the collection and cremation of the dead rats. This foreshadows the point during the epidemic when dead plague victims will meet the same fate. Moreover, everyone assumes that it is someone else's responsibility to take care of the swarm of dying rats. No one wants to depart from his or her comfortable, isolated routine to deal with the problem.
Many people do not want to admit that the rats pose a serious health risk to human beings, so they resort to rationalizing the phenomenon. M. Michel states that pranksters planted the dead rats in the building where he works. Dr. Rieux's asthma patient declares that hunger drove the rats out into the open to die. Both of these "rational" responses are actually completely irrational. Hunger does not explain the blood spurting from the rats' muzzles. M. Michel's explanation doesn't explain why there are hundreds of death rats in buildings all over the city.
On the phenomenon of the rats, Dr. Rieux states that it is as if an infected abscess had burst open, implying that Oran itself is diseased in some way. Over the course of the epidemic, it will become clear that indifference and denial constitute the metaphorical disease to which Rieux alludes. People are all too ready to deny that a collective problem does not concern them. It seems that the manager for the hotel where Tarrou is staying is more upset that "everyone is in the same boat" than he is with the disturbing implications of the plague of rats.
Tarrou's notebooks deal with a number of philosophical questions in addition to the small details of daily life in Oran. These notebooks constitute a large portion of Rieux's chronicle. This gives further support to the implication that Rieux's "chronicle" deals with issues far deeper than a journalistic catalogue of facts. Rieux's description of Oran's character implies that Oran's citizens are not living their lives to the fullest. Their narrow, circumscribed routines and their indifference prevents them from making the most of their finite existence--they are wasting their time. Tarrou's concern about wasting time echoes Rieux's own frustration with the Oran's time wasting tactics in response to the swarm of rats and later with the rising epidemic.
Tarrou posits that one does not waste time only when one is always aware of time. He muses that one can make oneself aware of time by indulging in intricate, frustrating, complicated routines. However, his suggestions for making oneself aware of time seem uncannily similar to the habitual routines that rob the residents of Oran of their sense of time: his philosophy is as meaningless as the meaninglessness it attempts to address. The coming epidemic will compel him to think of his question in a more meaningful light--in terms of life and death, individual and social responsibility. Simply being aware of time via constant frustration does not necessarily mean that one is not wasting time. Awareness of time is only one step in the process of actually making productive use of it.