It was a long day. Every time that a knock came to the door, or a sharp step passed in the street, I imagined that it was either Holmes returning or an answer to his advertisement. I tried to read, but my thoughts would wander off to our strange quest and to the ill-assorted and villainous pair whom we were pursuing. Could there be, I wondered, some radical flaw in my companion’s reasoning. Might he be suffering from some huge self-deception? Was it not possible that his nimble and speculative mind had built up this wild theory upon faulty premises? I had never known him to be wrong; and yet the keenest reasoner may occasionally be deceived. He was likely, I thought, to fall into error through the over-refinement of his logic,—his preference for a subtle and bizarre explanation when a plainer and more commonplace one lay ready to his hand. Yet, on the other hand, I had myself seen the evidence, and I had heard the reasons for his deductions. When I looked back on the long chain of curious circumstances, many of them trivial in themselves, but all tending in the same direction, I could not disguise from myself that even if Holmes’s explanation were incorrect the true theory must be equally _outré_ and startling. At three o’clock in the afternoon there was a loud peal at the bell, an authoritative voice in the hall, and, to my surprise, no less a person than Mr. Athelney Jones was shown up to me. Very different was he, however, from the brusque and masterful professor of common sense who had taken over the case so confidently at Upper Norwood. His expression was downcast, and his bearing meek and even apologetic. “Good-day, sir; good-day,” said he. “Mr. Sherlock Holmes is out, I understand.” “Yes, and I cannot be sure when he will be back. But perhaps you would care to wait. Take that chair and try one of these cigars.” “Thank you; I don’t mind if I do,” said he, mopping his face with a red bandanna handkerchief. “And a whiskey-and-soda?” “Well, half a glass. It is very hot for the time of year; and I have had a good deal to worry and try me. You know my theory about this Norwood case?” “I remember that you expressed one.” “Well, I have been obliged to reconsider it. I had my net drawn tightly round Mr. Sholto, sir, when pop he went through a hole in the middle of it. He was able to prove an alibi which could not be shaken. From the time that he left his brother’s room he was never out of sight of some one or other. So it could not be he who climbed over roofs and through trap-doors. It’s a very dark case, and my professional credit is at stake. I should be very glad of a little assistance.” “We all need help sometimes,” said I.