Joe picked it up quickly, and we rapped out messages to each other as soon as we were awake. For instance, three knocks, then after a pause two more, gave the letter H. This was the first of our morning's greetings, "Heeps better." Joe did not spell well at that time, but for the correction of his orthography it needed the schoolmaster's cane, and not a newly invented Morse sound code. So I let him spell as he liked. It lightened our days very much. And I will admit, ever after that, Joseph and I understood each other better. Now it will hardly be believed, but I am willing to let my commercial honour stand for the truth of what I am about to say, which with those who have done business with me will be sufficient. One morning I awoke early, before the slate-blue crack, with a star wandering across it, which was the jackdaw's front door, had changed to the grey of a winter's morning. I lay on my comfortless straw couch, wondering why it was that my prison was not colder. It could not be that it was so far underground as to be warm like the bottom of a mine, by its own distance from the earth's surface. There were the exits and the entrances of the jackdaws to witness against that. Still, though cold enough at times, the fact remained that the temperature of my prison never descended to the freezing point. Indeed, it had probably been chosen as a winter home by the birds on that account. Once or twice I had seen a flake of snow fluttering down, but these melted before they could be discerned on the oaken floor of the curious circular cellar in which I lay. I was, as I say, pondering over these things, about home, too, and what Joseph would be doing. I almost blush to write, but I began automatically knocking out a sentence in our old "Morse" code which had amused us during the fever year. "Is any one there?" I spelled the words out. And I actually sat upright with wonder when I heard come through the thick oak of the partition, first five distinct knocks, then, after a pause, one. [Illustration: "I heard first five distinct knocks then after a pause--one."] It was the letter E! But, then, only Joe and I knew of it! My heart sank. I thought in swift, lightning flashes. Had my son been captured also? But the person at the other side of the wall went on spelling, one knock, pause, three knocks. It was the letter L! And so with the quiet regularity of an expert, the sentence came back to me. "Elsie here--Who are you?" I felt much inclined, of course, to ask who Elsie might be, but I made my answer--fearing a trap--by the mere spelling out of my name and address, "Joseph Yarrow, Breckonside." Then there was tapped out hurried, imperfectly, in a manner denoting undue and even foolish emotion--"Dearest Joe. I thank you for trying to help me. Your Elsie."