“I assure you that I am simply here upon a visit to my friend, Sir Henry, and that I need no help of any kind.”

“Excellent!” said Stapleton. “You are perfectly right to be wary and discreet. I am justly reproved for what I feel was an unjustifiable intrusion, and I promise you that I will not mention the matter again.”

We had come to a point where a narrow grassy path struck off from the road and wound away across the moor. A steep, boulder-sprinkled hill lay upon the right which had in bygone days been cut into a granite quarry. The face which was turned towards us formed a dark cliff, with ferns and brambles growing in its niches. From over a distant rise there floated a grey plume of smoke.

“A moderate walk along this moor-path brings us to Merripit House,” said he. “Perhaps you will spare an hour that I may have the pleasure of introducing you to my sister.”

My first thought was that I should be by Sir Henry’s side. But then I remembered the pile of papers and bills with which his study table was littered. It was certain that I could not help with those. And Holmes had expressly said that I should study the neighbours upon the moor. I accepted Stapleton’s invitation, and we turned together down the path.

“It is a wonderful place, the moor,” said he, looking round over the undulating downs, long green rollers, with crests of jagged granite foaming up into fantastic surges. “You never tire of the moor. You cannot think the wonderful secrets which it contains. It is so vast, and so barren, and so mysterious.”

“You know it well, then?”

“I have only been here two years. The residents would call me a newcomer. We came shortly after Sir Charles settled. But my tastes led me to explore every part of the country round, and I should think that there are few men who know it better than I do.”

“Is it hard to know?”

“Very hard. You see, for example, this great plain to the north here with the queer hills breaking out of it. Do you observe anything remarkable about that?”

“It would be a rare place for a gallop.”

“You would naturally think so and the thought has cost several their lives before now. You notice those bright green spots scattered thickly over it?”

“Yes, they seem more fertile than the rest.”