the hour of ten o'clock
Should he attempt to scale the walls , he might be shot while so doing , and at any rate there was the moat beyond , which he could not possibly cross without detection . Seeking the deep shadow of an angle , the boy seated himself on a gun-carriage and pondered over the situation . The more he thought of it the more impossible did it seem for him to escape beyond the grim walls and meet Has-se at the appointed time . While he was thus overcome by the difficulties of his position , and as he had about concluded that he had undertaken an impossibility , he was startled by the deep tones of the great bell that hung in the archway of the gate , striking the hour of ten o'clock . Directly afterwards came the measured tramp of the guard and the clank of their weapons as they made their round for the purpose of relieving the sentinels on duty , and replacing them with fresh men . Réné sat so near the gate-way that he could overhear what was said when that post was relieved , and distinguishing above the rest the voice of his old friend Simon , the armorer , he became convinced that he had been placed on duty at this most important point . After relieving this post the guard resumed their march , and passed so close to where Réné sat in the shadow of the great gun that , had the night been a shade lighter , they must have seen him .