Trowelms gazed at the numbers he had noted down at the coordinates from the Griffin and the Bells.
"I deduce, Whyson, that this is part of a greater mystery," said the great detective.
"Indeed, Trowelms," I replied. "But has more intelligence come to light that reinforces your deduction?"
"Why, Whyson, how can you have failed to notice the piece of parchment pinned to the front door as you entered?"
Embarrassingly, I had to admit that I had not. I immediately descended the stairs and opened the front door, so that I could observe this new marvel.
There, just as Trowelms had said, was pinned a large sheet of parchment and written upon this sheet was written 'The Butlers did it'.
Finally furnished with this new information, I returned to where Trowelms waited impatiently. "Well, Whyson? What do you make of that?"
"I haven't the foggiest, Trowelms," I replied.
"Hmmm," came the response from Hemlock Trowelms, as his lit his pipe. "Did you happen to look on the reverse of the parchment?"
Once more (after advising Trowelms to lay off the pipe for a while, given his over indulgence when studying the case of the Griffin and the Bells), I descended the stairs to the front door. This time, I thought, I shall bring the damn thing upstairs with me!
I returned to Trowelms and examined the reverse of the item. "I don't see a thing, Trowelms," I observed.
"Hand me the parchment," he responded.
I did so and he immediately thrust the parchment over the flame of the candle he used to read by. As he held it there, markings began to be revealed.
"What's this, Trowelms?" I said in astonishment. "Witchcraft!"
"Nothing so interesting, Whyson," he replied, "just more coordinates, written in lemon juice to keep them concealed and the letters H and C along with a simple diagram of what appeared to be a two-headed dog. It suggests to me that a pair of gentleman's valets are the culprits in this portion of the puzzle. Our paths have crossed before.
"Come, Whyson, there's not a moment to waste! Let us away!"