Short answers, pulled from the story.
The Plague is a 1947 absurdist novel set in the French Algerian city of Oran during a bubonic plague outbreak and citywide quarantine. It follows a group of characters including a doctor, a journalist, a vacationer, and a priest as they respond to mass death, isolation, and the collapse of ordinary life. Camus uses the epidemic to explore themes of human solidarity, powerlessness, and the tension between faith and suffering.
Camus drew on the cholera epidemic that killed a large proportion of Oran's population in 1849, though he set the novel in the 1940s. Oran also suffered outbreaks of bubonic plague in 1556 and 1678, and smaller outbreaks in 1921 (185 cases), 1931 (76 cases), and 1944 (95 cases), none of which approached the scale of the novel's fictional epidemic.
As early as April 1941, Camus was recording ideas about "the redeeming plague" in his diaries. On the 13th of March 1942, he informed the novelist André Malraux that he was writing "a novel on the plague". The finished novel was published in 1947.
The novel has been widely read as an allegory of the French resistance to Nazi occupation during World War II, given that Camus wrote it while France was occupied. Journalist Carlos Maza also drew parallels between the novel and more recent events including Trumpism and the COVID-19 pandemic.
At the close of the novel, Doctor Rieux reveals himself as the narrator. He states that he tried to present an objective account of events and wrote the chronicle to show that, even in crisis, people are more good than evil. The plague retreats by late January, the town gates reopen in February, and people are reunited with loved ones, though Tarrou dies of the plague just before the end of the quarantine.
The novel's depiction of a city under quarantine closely paralleled real-life COVID-19 lockdowns, driving a surge in sales during 2020. In Italy, sales tripled during the nationwide lockdown, and The Plague became a top-ten bestseller there. Penguin Classics reported difficulty keeping up with demand, and Camus's daughter Catherine said the novel had newfound relevance because "we are not responsible for coronavirus but we can be responsible in the way we respond to it".