From an unreflective, instinctive, mechanical feeling, the lieutenant cried:

“Fire!”

Immediately a volley of musketry flamed, thundered, roared in the cavern, bringing down enormous fragments from the vaults. The cavern was lighted for an instant by this discharge, and then immediately returned to pitchy darkness rendered thicker by the smoke. To this succeeded a profound silence, broken only by the steps of the third brigade, now entering the cavern.