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 overrefinement 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.