Fitted close as books on a shelf, squared and built with little mortar, the task of loosening and completely disengaging one stone occupied hours. The knife bent like a willow wand; and the earl's heart almost sunk with fear lest it should break, and that if he failed or was discovered at such a task, a stronger prison, perhaps a hopeless dungeon, might be apportioned to him. Loosened on all sides, the stone he had selected was a block a foot high by eighteen inches broad; it vibrated to the touch, but the utmost exertion and art he could put in practice failed to coax it one inch from its deep bed in the wall; the knife, his nails, his fingers, were all resorted to successively again and again, but in vain--it shook, it vibrated, but obstinately remained in its place, till in a fit of fury, and when about to abandon the task in despair, he uttered a malediction, and gave the stone a violent push with both his hands! Then, lo! it shot through the wall to the outside, and disengaging others in its passage, fell upon what Lord Ashkirk discovered in a moment to be a step of one of those narrow stairs we have described in the preceding chapter. The echoes of its fall died away in the stony windings of the stair; and grasping his knife, the earl stood for a moment petrified, lest all his labour and anxiety were lost, and the noise should rouse the household; but fortunately (save their master) all the members of it were buried in profound repose. The earl could hear his heart beating, as the blood rushed back tumultuously upon it; but all remained still as death, and he could hear the corbies croaking as they swung in their nests among the foliage of the ancient trees without. There was not a moment to be lost. With some difficulty he crawled through the aperture, and found himself in a dark and narrow stair. His first thought was to replace the heavy stone, which he did with ease, for this gallant young noble was strong as a Hercules; thus, as the breach was immediately behind the door, it was concealed from those who might enter the chamber; and hence the dismay of Tam Trotter on the morrow, when he found it void, without knowing or perceiving how. The earl was naturally about to descend, when the cry of a female arrested him; and though he knew not with certainty that his sister Jane was in the power of Sir Adam Otterburn, the voice made him experience something like an electric shock; and he sprang up the stair, taking three steps at a time. The first apartment he entered was empty; a light burned on the table, which bore a pyramid of letters and papers; the walls were shelved, and covered with vellum-bound volumes--it was the study or library of the lord advocate. A Flemish clock, in workmanship and aspect little superior to a common roasting-jack of modern times, hung above the mantel-piece, and pointed to the hour of twelve.