As a feat of uninterrupted talking (for, unlike Bobby, Campbell made no attempt even to ask a question) it was the nearest approach to a record that I am ever likely to achieve. Long before I had finished my voice was as hoarse as a crow's, and even now I can remember the feeling of relief with which I lay back in my chair when it was all over, and gazed expectantly into the shrewd, wide-awake eyes of my apparently unwearied companion. It was he who was the first to break the silence. "I congratulate you on a really remarkable performance, Mr. Dryden," he observed. "I have never met anyone who would make a better witness." "Well, if that's the case," I replied, "I hope to God my abilities will be wasted." Campbell looked at me for a moment with a queer, half-quizzical smile; then very suddenly his expression changed to one of the utmost gravity. "Aye," he said in his harsh North country accent, "it's a serious enough matter in all conscience. The pity is that you couldn't come to me before. It might have saved one poor fellow's life anyway." "You believe that Bascomb was murdered then?" I answered slowly. "I'm sure of it," was the grim reply, "and, what's more, I'm practically certain that every word which that young lady told you is the Gospel truth." He sucked in his upper lip, and sat there for a moment gnawing the end of his short stubbly moustache. "It's curious what a fool one can be at times," he continued. "I've been looking out for those stones ever since the Brazilian Government sent round their first notice. Twenty per cent was the offer they made, and on their own original estimate that would have worked out at something like forty thousand pounds. There isn't a police officer or detective in Europe who hasn't tried his hand on the job--and to think that for the last three months I've been walking around with the blessed things right under my very nose!" "Oh, hang the diamonds!" I exclaimed. "We've got something more important to think about than them." "Quite so," assented Campbell drily. "All the same, you may find the subject of some interest--after we've settled with Dr. Manning." "Have you any doubt in your own mind as to whether he killed Bascomb?" I asked. "I should think it's more likely to have been Craill," was the answer. "There was a touch of crudeness about the affair which doesn't quite fit in with our friend's record." I leaned forward eagerly. "You've traced him?" I exclaimed. "You've found out who he is?" Campbell pulled open a drawer in the table beside him and took out a piece of paper.