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.