The Plague by Albert Camus (1947)

First the rats come up to die in the open, on stairwells and in the street, and the town of Oran is too comfortable to read the warning. Then the gates close, the city is quarantined from the world, and Dr. Bernard Rieux begins the work that fills the book: tending the dying, not out of heroism but because the alternative would be unthinkable. Camus strips every consolation away. There is no divine plan, no reward, only the daily refusal to let people suffer alone, and he insists this stubborn decency is the only sanity left when the world stops making sense. The novel's most unbearable hour comes when a child dies slowly in front of a priest who has called the plague God's justice, and that God does not survive the bedside. Camus wrote Oran as occupied France, but the last pages reach further: the bacillus never truly dies, only waits, patient in cupboards and old papers, ready to rouse its rats again in some happy, forgetful city.