On 26 April 1803 thousands of stones fell on the commune of L'Aigle, in Lower Normandy. The Institute commissioned a young physicist to investigate this phenomenon that intrigued the scholars. Jean-Baptiste Biot arrived at L'Aigle on the evening of 30 June. For six days he combed the bocage in search of the stones fallen from the sky and questioned many witnesses of the fall. Back in Paris he wrote a detailed report whose lapidary conclusion, "stones have fallen at L'Aigle", brought meteorites into the field of science. In autumn 2017 Julien Magre and Matthieu Gounelle went to L'Aigle equipped with the map drawn by Biot more than two centuries earlier. Walking, they devised this book on stones, the sky and absence.