The first step having thus been gained, I began to devote myself earnestly to the problem of escape. I did not make light of the difficulties. The only entrance to the castle precincts was, as I have said, the gateway at the end of the drawbridge, and this was so stoutly guarded that escape in daylight was impossible. At night we were locked in the dormitory nearly thirty feet above ground, with a thick stone wall between us and freedom, and supposing we could make a hole in the wall, which seemed unlikely, there was still the moat to be reckoned with. It was not only too far below for any one to dive into it with safety, but it was, as I had learned from the soldiers, choked with mud to within a very little of the surface, so that I could not but doubt whether it were possible even to swim across. But I did not despair of crossing it if we could only get down: that was the difficulty, and for long tedious weeks it seemed to me insuperable. Before we had hit upon a plan, we were thrown into a great excitement by the disappearance of Vetch. I had missed him for a day or two from the courtyard, but thought little of it, supposing that he was confined to his dormitory by a touch of fever, as happened not infrequently among the prisoners. But on Punchard's remarking one day that he believed Vetch was malingering, it came out that he had not been seen by his roommates for nearly a week. Was it possible that while we had been merely thinking of escape, Vetch had found a means of escaping? It seemed impossible, and when I was having my daily conversation with the soldiers of the guard, I asked point blank what had become of him. They laughed and chuckled, and amused themselves for some time by giving all manner of fantastic explanations, which improved my knowledge of French, but were mightily vexatious. At last I made out, from hints and half statements, that the commandant had been discreetly inquiring among some of the prisoners for a man who was well acquainted with the river Avon. Since these inquiries ceased and Vetch disappeared about the same time, I was free to conclude that in Vetch the commandant had found his man. Had he purchased his freedom at the price of treason to his country? Were the French meditating an attack on Bristowe? These were questions I could not answer; but you may be sure the knowledge that Vetch was gone acted as a whip to my determination, and I was more than ever resolved to find some way of leaving these walls behind.