In June 1940, while scouting for the army following him, a young German lieutenant rode a BMW motorbike toward Montmartre, using the brilliant dome of Sacré-Coeur as his beacon. He found the streets empty, but upon reaching the center of the neighborhood, he saw his first Parisians, and they their first German occupier. The soldier quickly sped away, but the abashed citizens now realized that Paris was no longer theirs alone.

After a lightning-speed defeat by the Germans in May-June 1940, France, and especially Paris, confronted what was quickly named la peste brune (the brown plague, referring to the color of German uniforms), an epithet derived from la peste noire (the Black Plague, nestled in collective memory). Plagues—real and metaphorical—cross all lines, reduce to meaningless all worldly categories, confound the intelligent with the stupid, produce what the French economist Thomas Piketty identifies as the “violence of inequality.” Victims of plagues are confounded by the options offered them. They have to relearn, if not reimagine, what had been essentially automatic behavior. Soon, a smothering bureaucracy, devised by both the Germans and their fellow travelers, the right-wing French government in Vichy, would upend life in the city that had stood through centuries for liberty and tolerance.