“Bogs make queer noises sometimes. It’s the mud settling, or the water rising, or something.”

“No, no, that was a living voice.”

“Well, perhaps it was. Did you ever hear a bittern booming?”

“No, I never did.”

“It’s a very rare bird—practically extinct—in England now, but all things are possible upon the moor. Yes, I should not be surprised to learn that what we have heard is the cry of the last of the bitterns.”

“It’s the weirdest, strangest thing that ever I heard in my life.”

“Yes, it’s rather an uncanny place altogether. Look at the hillside yonder. What do you make of those?”

The whole steep slope was covered with grey circular rings of stone, a score of them at least.

“What are they? Sheep-pens?”

“No, they are the homes of our worthy ancestors. Prehistoric man lived thickly on the moor, and as no one in particular has lived there since, we find all his little arrangements exactly as he left them. These are his wigwams with the roofs off. You can even see his hearth and his couch if you have the curiosity to go inside.

“But it is quite a town. When was it inhabited?”

“Neolithic man—no date.”

“What did he do?”

“He grazed his cattle on these slopes, and he learned to dig for tin when the bronze sword began to supersede the stone axe. Look at the great trench in the opposite hill. That is his mark. Yes, you will find some very singular points about the moor, Dr. Watson. Oh, excuse me an instant! It is surely Cyclopides.”

A small fly or moth had fluttered across our path, and in an instant Stapleton was rushing with extraordinary energy and speed in pursuit of it. To my dismay the creature flew straight for the great mire, and my acquaintance never paused for an instant, bounding from tuft to tuft behind it, his green net waving in the air. His grey clothes and jerky, zigzag, irregular progress made him not unlike some huge moth himself. I was standing watching his pursuit with a mixture of admiration for his extraordinary activity and fear lest he should lose his footing in the treacherous mire, when I heard the sound of steps and, turning round, found a woman near me upon the path. She had come from the direction in which the plume of smoke indicated the position of Merripit House, but the dip of the moor had hid her until she was quite close.