It was a wild morning in October, and I observed as I was dressing how the last remaining leaves were being whirled from the solitary plane tree which graces the yard behind our house. I descended to breakfast prepared to find my companion in depressed spirits, for, like all great artists, he was easily impressed by his surroundings. On the contrary, I found that he had nearly finished his meal, and that his mood was particularly bright and joyous, with that somewhat sinister cheerfulness which was characteristic of his lighter moments.

“You have a case, Holmes?” I remarked.

“The faculty of deduction is certainly contagious, Watson,” he answered. “It has enabled you to probe my secret. Yes, I have a case. After a month of trivialities and stagnation the wheels move once more.”

“Might I share it?”