“Thank you. We have certainly been favoured with extraordinary luck during this inquiry, and it will be entirely our own fault if we do not succeed in clearing the matter up. With your permission, Mr. Holder, I shall now continue my investigations outside.”

He went alone, at his own request, for he explained that any unnecessary footmarks might make his task more difficult. For an hour or more he was at work, returning at last with his feet heavy with snow and his features as inscrutable as ever.

“I think that I have seen now all that there is to see, Mr. Holder,” said he; “I can serve you best by returning to my rooms.”

“But the gems, Mr. Holmes. Where are they?”

“I cannot tell.”

The banker wrung his hands. “I shall never see them again!” he cried. “And my son? You give me hopes?”

“My opinion is in no way altered.”

“Then, for God’s sake, what was this dark business which was acted in my house last night?”

“If you can call upon me at my Baker Street rooms to-morrow morning between nine and ten I shall be happy to do what I can to make it clearer. I understand that you give me carte blanche to act for you, provided only that I get back the gems, and that you place no limit on the sum I may draw.”

“I would give my fortune to have them back.”

“Very good. I shall look into the matter between this and then. Good-bye; it is just possible that I may have to come over here again before evening.”

It was obvious to me that my companion’s mind was now made up about the case, although what his conclusions were was more than I could even dimly imagine. Several times during our homeward journey I endeavoured to sound him upon the point, but he always glided away to some other topic, until at last I gave it over in despair. It was not yet three when we found ourselves in our room once more. He hurried to his chamber, and was down again in a few minutes dressed as a common loafer. With his collar turned up, his shiny, seedy coat, his red cravat, and his worn boots, he was a perfect sample of the class.

“I think that this should do,” said he, glancing into the glass above the fireplace. “I only wish that you could come with me, Watson, but I fear that it won’t do. I may be on the trail in this matter, or I may be following a will-o’-the-wisp, but I shall soon know which it is. I hope that I may be back in a few hours.” He cut a slice of beef from the joint upon the sideboard, sandwiched it between two rounds of bread, and thrusting this rude meal into his pocket he started off upon his expedition.

I had just finished my tea when he returned, evidently in excellent spirits, swinging an old elastic-sided boot in his hand. He chucked it down into a corner and helped himself to a cup of tea.

“I only looked in as I passed,” said he. “I am going right on.”

“Where to?”

“Oh, to the other side of the West End. It may be some time before I get back. Don’t wait up for me in case I should be late.”

“How are you getting on?”

“Oh, so so. Nothing to complain of. I have been out to Streatham since I saw you last, but I did not call at the house. It is a very sweet little problem, and I would not have missed it for a good deal. However, I must not sit gossiping here, but must get these disreputable clothes off and return to my highly respectable self.”

I could see by his manner that he had stronger reasons for satisfaction than his words alone would imply. His eyes twinkled, and there was even a touch of colour upon his sallow cheeks. He hastened upstairs, and a few minutes later I heard the slam of the hall door, which told me that he was off once more upon his congenial hunt.