“Of course there is,” he said. “There are a hundred explanations, all of which are quite satisfactory. I suppose you had the keys out together on the table, and they got mixed at some time or other, and you did not notice. I’m not suggesting that you can’t explain. I merely point out this fact, which at present has no bearing, or very little, on any aspect of the case.” Lewinstein and the detective went from the house together. His lordship, left alone, paced the study restlessly. Then he sat down at his desk and began to write. He produced two large canvas envelopes from the drawer of his desk, and into one of these he inserted a square certificate. He examined it casually before he put it into the cover. It was a debenture certificate issued by the North American Smelter Corporation for five hundred thousand dollars, and there was a particular reason why he should not have this valuable and important document in his house. He addressed the envelope containing the cover to himself in London. This he crossed with blue pencil, and from a drawer took out a small box containing a number of unused stamps. They were not British stamps, but Colonial, including Australian, African, Indian, and British Chinese. He fixed two Australian stamps, and placed the envelope within another, a little bigger. This he addressed to the manager of a Tasmanian bank, with whom he had done some business. To this gentleman he wrote a letter, saying that he expected to be in Australia by the time this letter reached it’s destination. “But,” the letter went on, “if by any chance I am not able to get to Australia, and I do not call for this packet within a week after its arrival, or notify you by cable, asking you to keep it for me, will you please send it back to me by registered post.” That was a job well done, he thought, as he sealed the envelope. This incriminating document would at any rate be out of the country for three months. Should he register it? He scratched his chin dubiously. Registration literally meant registration. If people inquired as to whether he had made any important transfer by mail, there would be no difficulty in discovering, not only the fact that he had posted such a letter, but the address to which it had been posted. No, on the whole he thought it would be better if he sent the letter by ordinary post. He put on his hat and coat, and took the letter himself to the nearest post office. On his return his butler announced a visitor. “Miss Wilberforce!” said his lordship in surprise, “I thought she was in the country.” “She arrived a few minutes after you left, m’lord.” “Excellent!” said Claythorpe. It was the last person he had expected to see, and he fetched a sigh of relief. It might have been awkward if she had arrived earlier--at any rate, it was a remarkable coincidence that she had come at all that evening. He found her standing by his table, and went towards her with outstretched hands.