I was asked to give the great man a day or two for solitary contemplation after the completion of our last adventure, so I willingly complied. Trowelms could be a difficult man to be in the company of, at times, especially when his mind was taken up with a case. And there's only so much pipe smoke a man can inhale without becoming as wheezy as the one producing it.
After the requisite period had passed, I returned to 221c Baker Street, refreshed and ready to continue with the puzzle which had kept us occupied all this time.
"Whyson!" exclaimed Trowelms, as I entered his rooms, "perfect timing, as always!"
He beckoned me over to his desk and thrust a magnifying glass into my hand. "Look at this. I acquired it from an antiquarian acquaintance of mine, who was aware, in some small part, of our current quest…and he has, I think, given us the final piece of the puzzle!"
I had rarely heard Trowelms so verbose, as he excitedly handed me an ancient coin. It was in particularly good condition, for a piece so old, with the exception of a 'D' which had recently been engraved on the front face. Quite pleased with myself that I'd noticed something important, I pointed my discovery out to Trowelms.
"Yes, yes, Whyson. Elementary." He sighed. "Looked around the rim."
I turned the coin to look at the edge and could just make out some more engraving. It was very small, and the age of the coin did not make my examination easier, but I could just make out some more coordinates.
"Is this the location of the last clue, Trowelms?" I enquired.
"Whyson, I do believe that it is!" Trowelms said, walking swiftly to where his coat hung. "Let us be off!"