Now a man in Bob Shaftoe's trade owed his longevity, in part, to his alertness – his sensitivity to (among other things) significant noises. Even the dimmest recruits could be relied on to notice the loud noises. A senior man like Bob was supposed to scrutinize the faint ones. Eliza got the impression that Bob was the sort of bloke who was forever shushing every man in the room, demanding absolute stillness so that he could hold his breath and make out whether that faint sporadic itching was a mouse in the cupboard, or enemy miners tunnelling under the fortifications. Whether that distant rhythm was a cobbler next door or an infantry regiment marching into position outside of town.