"Well, apart from this cigarette-end, was it not suggestive that theonly time the lodger went out was immediately after his taking therooms? He came back- or someone came back- when all witnesses were outof the way. We have no proof that the person who came back was theperson who went out. Then, again, the man who took the rooms spokeEnglish well. This other, however, prints 'match' when it shouldhave been 'matches.' I can imagine that the word was taken out of adictionary, which would give the noun but not the plural. Thelaconic style may be to conceal the absence of knowledge of English.Yes, Watson, there are good reasons to suspect that there has been asubstitution of lodgers."

　　"But for what possible end?"

　　"Ah! there lies our problem. There is one rather obvious line ofinvestigation." He took down the great book in which, day by day, hefiled the agony columns of the various London journals. "Dear me!"said he, turning over the pages, "what a chorus of groans, cries,and bleatings! What a rag-bag of singular happenings! But surely themost valuable hunting-ground that ever was given to a student of theunusual! This person is alone and cannot be approached by letterwithout a breach of that absolute secrecy which is desired. How is anynews or any message to reach him from without? Obviously byadvertisement through a news paper. There seems no other way, andfortunately we need concern ourselves with the one paper only. Hereare the Daily Gazette extracts of the last fortnight. 'Lady with ablack boa at Prince's Skating Club'- that we may pass. 'Surely Jimmywill not break his mother's heart'- that appears to be irrelevant. 'Ifthe lady who fainted in the Brixton bus'- she does not interest me.'Every day my heart longs-' Bleat, Watson- unmitigated bleat! Ah, thisis a little more possible. Listen to this: 'Be patient. Will find somesure means of communication. Meanwhile, this column. G.' That is twodays after Mrs. Warren's lodger arrived. It sounds plausible, doesit not? The mysterious one could understand English, even if hecould not print it. Let us see if we can pick up the trace again. Yes,here we are- three days later. 'Am making successful arrangements.Patience and prudence. The clouds will pass. G.' Nothing for a weekafter that. Then comes something much more definite: 'The path isclearing. If I find chance signal message remember code agreed- one A,two B, and so on. You will hear soon. G.' That was in yesterday'spaper, and there is nothing in to-day's. It's all very appropriateto Mrs. Warren's lodger. If we wait a little, Watson, I don't doubtthat the affair will grow more intelligible."

　　So it proved; for in the morning I found my friend standing on thehearthrug with his back to the fire and a smile of completesatisfaction upon his face.

　　"How's this, Watson?" he cried, picking up the paper from the table.'High red house with white stone facings. Third floor. Second windowleft. After dusk. G.' That is definite enough. I think after breakfastwe must make a little reconnaissance of Mrs. Warren's neighbourhood.Ah, Mrs. Warren! what news do you bring us this morning?"Our client had suddenly burst into the room with an explosive energywhich told of some new and momentous development.