“His companion!”

Holmes pulled a large sheet of tissue-paper out of his pocket and carefully unfolded it upon his knee.

“What do you make of that?” he asked.

The paper was covered with the tracings of the footmarks of some small animal. It had five well-marked footpads, an indication of long nails, and the whole print might be nearly as large as a dessertspoon.

“It’s a dog,” said I.

“Did you ever hear of a dog running up a curtain? I found distinct traces that this creature had done so.”

“A monkey, then?”

“But it is not the print of a monkey.”

“What can it be, then?”