Midnight
But the air seemed oppressive . He felt that there was treachery in it , and , rising , he bolted and barred the door of his room , and placed his trusty sword within reach of his hand . Still he could not rest , and tossed about , seeing both the hard face of De Roberval before him , and the rugged outlines of the barren , northern island with the beckoning smoke curling upward . Midnight came ; and when everything was at rest save the clink , clank of the sentry 's footfall as he walked back and forth on the wall , La Pommeraye raised himself on his elbow , and listened . A rat seemed to be gnawing at the wall . `` Hard food , these stones , '' he said to himself . `` Methinks , '' he added , as the sound grew louder , `` the rat hath strong teeth . ''