A lost river, a lost aunt, a found literary life: from the cult-favourite poet and author of The Baudelaire Fractal comes a glittering and erudite new novel of Paris. Some ruins are invisible. Under the pavements of Paris there lies buried an ancient river, the Bievre. For years, Lucy Frost has walked along these streets, unaware of the water and history under her feet, on her way to clean the apartments of Paris's academic class. As she begins to study and transcribe the inherited notebooks and papers of her great-aunt, a teacher and researcher who disappeared years earlier, she commits to continuing her aunt's youthful research on the Bievre, mining the river's documentary traces in the works of Rousseau, Rabelais, Hugo, Chateaubriand, and the like. She uncovers a history of industry: paper mills, dyeing workshops, tanneries, and textile manufacturers and laundries. She finds resonances of her own labour in the history of the river's laundresses. On stolen time at work, and in her