I was looking with great anticipation to the violin concert that my friend, Sherlock Holmes, had suggested. Though late in the evening, he had astonished me yet again with how quickly, from his first casual mention of the item displayed in the Times, he had washed and finished dressing. It took me somewhat longer to ready myself for our departure. When he so desires, Holmes seems to demonstrate, at a moment’s notice, his remarkable ability to whip into action. By the time I was done, he had a hansom waiting for us at the door.

We had just alighted from our carriage, during which time he commented on the rather late hour, when we were distracted by a crowd forming on the other side of the avenue. The congregation seemed to be in the general direction of the theatre, our destination. Despite my concerns for missing the beginning strains of the concert, he insisted on diverting our path to the commotion.

Inspector Gregson, though surprised to see us, stood in its midst and greeted us enthusiastically. He pointed to a prostrate form, a woman, lying in a pool of blood. Gregson, misinterpreting our arrival there, immediately produced a piece of paper and handed it to us. The paper, on which a badly scrawled letter "N" was displayed, seemed quite ordinary. Holmes looked it over intensely.

After some moments, I asked him about cancelling our plans for the concert.

"Nonsense, Watson," he said suddenly, picking up his head to look at me, then at Gregson, and handed the paper back to the inspector. "The chambermaid did this."

I, as well as the inspector, stared at him in shock, not knowing what to say. I finally said, "But how can you say this?"

He looked at me sharply, his face betraying mock astonishment, and said: “You know my methods, Watson. Use them.”

With that he casually walked away, a hint of a smile on his lips.

He never fails to astonish me.