At the end of the Middle Ages, in Florence, Italy, a revolt of the poorest textile workers, the Ciompi, upsets the city and succeeds in overthrowing the government. In Florence, I film in their footsteps to bring out the ghosts of this revolt. In the industrial suburbs, I discover the echoes in the present, in the modern textile factories where immigrant workers are exploited. In Paris, I dialogue with the militant researcher who made the history of the revolt. Together we question the political stakes of writing history in the construction of a fertile collective memory.