She looked at me with a surprised face.
'For God's sake put such an idea out of your mind,' said she. 'Your blood would be upon my head. I assure you that there would not be the least chance of your coming back alive. It is only by remembering certain complex landmarks that I am able to do it.'
'Halloa!' I cried. 'What is that?'
A long, low moan, indescribably sad, swept over the moor. It filled the whole air, and yet it was impossible to say whence it came. From a dull murmur it swelled into a deep roar, and then sank back into a melancholy, throbbing murmur once again. Stapleton looked at me with a curious expression in her face.
'Queer place, the moor!' said she.
'But what is it?'
'The peasants say it is the Hound of the Baskervilles calling for its prey. I've heard it once or twice before, but never quite so loud.'
I looked round, with a chill of fear in my heart, at the huge swelling plain, mottled with the green patches of rushes. Nothing stirred over the vast expanse save a pair of ravens, which croaked loudly from a tor behind us.
'You are an educated woman. You don't believe such nonsense as that?' said I. 'What do you think is the cause of so strange a sound?'
'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 hill- side yonder. What do you make of those?'
The whole steep slope was covered with gray 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 woman lived thickly on the moor, and as no one in particular has lived there since, we find all her little arrangements exactly as she left them. These are her wigwams with the roofs off. You can even see her hearth and her 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 she do?'
'She grazed her cattle on these slopes, and she 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 her 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, her green net waving in the air. Her gray clothes and jerky, zigzag, irregular progress made her not unlike some huge moth herself. I was standing watching he
r pursuit with a mixture of admiration for her extraordinary activity and fear lest she should lose her footing in the treacherous mire, when I heard the sound of steps, and turning round found a man near me upon the path. He 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 his until he was quite close.
I could not doubt that this was the Mister Stapleton of whom I had been told, since ladies of any sort must be few upon the moor, and I remembered that I had heard someone describe his as being a beauty. The man who approached me was certainly that, and of a most uncommon type. There could not have been a greater contrast between sister and brother, for Stapleton was neutral tinted, with light hair and gray eyes, while he was darker than any brunette whom I have seen in England--slim, elegant, and tall. He had a proud, finely cut face, so regular that it might have seemed impassive were it not for the sensitive mouth and the beautiful dark, eager eyes. With his perfect figure and elegant dress he was, indeed, a strange apparition upon a lonely moorland path. His eyes were on his sister as I turned, and then he quickened his pace towards me. I had raised my hat and was about to make some explanatory remark, when his own words turned all my thoughts into a new channel.
'Go back!' he said. 'Go straight back to London, instantly.'
I could only stare at him in stupid surprise. His eyes blazed at me, and he tapped the ground impatiently with his foot.
'Why should I go back?' I asked.
'I cannot explain.' He spoke in a low, eager voice, with a curious lisp in his utterance. 'But for God's sake do what I ask you. Go back and never set foot upon the moor again.'