"Two days ago I had a letter from Ridsdale in which he told me that he intended to put the matter into your hands. Now this was by no means to my mind, for you, Bell, happened to be the one man in the world whom I really dreaded. I saw that I must no longer lose time. Under my little boat-house I had a small submarine boat which I had lately finished, more as a hobby than anything else. I had begun it years ago in my odd moments on a model I had seen of a torpedo used in the American War. My boat is now in the lock outside, and you will see for yourself what ingenuity was needed to construct such a thing. On the night before the one which has just passed, I got it ready, and, as soon as it was dark, started off in it to recover the diamonds. I got through the lock easily by going in under the water with a barge, but when I reached the spot where I had sunk the diamonds, found to my dismay that my electric light would not work. There was no help for it--I could not find the bracelet without the aid of the light, and was bound to return home to repair the lamp. This delay was fraught with danger, but there was no help for it. My difficulty now was to get back through the lock; for though I waited for quite three hours no boats came along. I saw the upper gates were open, but how to get through the lower ones I could not conceive. I felt sure that my only chance was to frighten the lock-keeper, and get him to open the sluices, for I knew I could pass through them unobserved if they were open, as I had done once before. "In my diver's helmet was a thick glass face-piece. This had an opening, closed by a cap, which could be unscrewed, and through which I could breathe when above water, and also through which my voice would come, causing a peculiar hollowness which I guessed would have a very startling effect, especially as I myself would be quite invisible. I got into the lock, and shouted to Pegg. I succeeded in frightening him; he hurried to do what I ordered. He wound up the lower sluice, I shot through under water, and so got back unseen. All yesterday I hesitated about trying the experiment again, the risk was so great; but I knew that Ridsdale was certain to see his bank-book soon, that my forgery was in imminent danger of being discovered, also that you, Bell, were coming upon the scene. "Yes, at any risk, I must now go on. "I repaired my light, and again last night passed through the lock on my way up, by simply waiting for another boat. As a matter of fact, I passed up through this lock under a skiff about eleven o'clock. My light was now all right, I found the diamond case easily, and turned to pass down the stream by the same method as before. If you had not been here I should have succeeded, and should have been safe, but now it is all up." He paused, and his breath came quickly. "I doubt if I shall recover," he said in a feeble voice. "I hope you will," I replied; "and hark! I think I hear the doctor's steps."