midnight
He took the file out of his mattress , and placed it in his breast : let that man beware who found it there ! At last the long night , which should have found him free , passed by , and the next weary day . The appointed time had come . It was past midnight , and not a sound was heard in the vast prison ; there was no moon , but a few stars shone on him as he worked at the iron bars ; the noise of his file was muffled -- he had rubbed it well with soap -- but every now and then he paused and listened . He half fancied he could hear the distant tramp of the patrols , who , musket in hand , watched the walls of Lingmoor from the roofs of its four stone towers ; but it was only fancy , and , at all events , no one else but they was stirring . Years ago he had gauged those bars , and calculated that not less than three must be sawn through to give his body room to pass ; but that was when he was young and plump and vigorous . He was vigorous now -- the fever within him seemed to give him the strength of ten -- but he was an old man to look at , and the flesh had left his bones .