As the lights went out on the city-well of Babel, all of its residents knew that something bad had happened. Once daylight returned, the body of a man was found in the ventilation ducts, leaving as the only clue to his identity, a burnt book. Eulalie 23 2P, an archivist, is then asked by an investigator from the underworld to make the book talk, to put a name on the unknown man and perhaps trace him to his murderer. But while searching her records, the young woman discovers that the book is part of a long list of stolen books. When a second body is found, drained of blood, the joint search of the investigator and the archivist becomes more urgent. Will they succeed in following their respective leads before the next one?