Read it through once

After some further talk, in which the Lord St. John covered up his mistake as well as he could by repeated protests that his faith was thoroughly grounded now, and could not be assailed by doubts again, the Lord Hertford relieved his fellow-keeper, and sat down to keep watch and ward alone. He was soon deep in meditation, and evidently the longer he thought, the more he was bothered. By-and-by he began to pace the floor and mutter.