midnight
Under the guidance of the half-blood Antonio , an open glade is found near the centre of the thicket . Here the horsemen dismount and tie their horses to the trees . The attack is to be made on foot . It is now the hour after midnight . The moon has been down for some time ; and the cirrus clouds , that for a while had reflected her light , have been gradually growing darker . Objects can no longer be distinguished at the distance of twenty feet . The huge pile of the Presidio , looming against the leaden sky , looks black and gloomy .