The narrative follows the doubting Abbe Pierre Froment as his pilgrimage from religious certainty to skeptical engagement unfolds amid the city's social life, juxtaposing Catholic institutions with emerging science, labor struggles, and anarchist and socialist movements. Interwoven episodes present portraits of bankers, factory workers, politicians, journalists, artists, and activists; public scenes include parliamentary debates, trials and an execution, social salons, and the streets and theaters. Through symbolic characterization and vivid social detail, the work examines faith's erosion, conflicts over capital and labour, and the search for a secular ethos grounded in reason and everyday experience.