Then a long, agonized, writhing neck shot upward and a dreadful cry echoed over the moor. It turned me cold with horror, but my companion's nerves seemed to be stronger than mine.
`It's gone!' said he. `The mire has him. Two in two days, and many more, perhaps, for they get in the way of going there in the dry weather and never know the difference until the mire has them in its clutches.
It's a bad place, the great Grimpen Mire.'
`And you say you can penetrate it?'
`Yes, there are one or two paths which a very active man can take.
I have found them out.'
`But why should you wish to go into so horrible a place?'
`Well, you see the hills beyond? They are really islands cut off on all sides by the impassable mire, which has crawled round them in the course of years. That is where the rare plants and the butterflies are, if you have the wit to reach them.'
`I shall try my luck some day.'
He looked at me with a surprised face.
`For God's sake put such an idea out of your mind,' said he.
`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 his face.
`Queer place, the moor!' said he.
`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 man. 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 hillside 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 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 gray 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.
I could not doubt that this was the Miss 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 her as being a beauty. The woman who approached me was certainly that, and of a most uncommon type. There could not have been a greater contrast between brother and sister, for Stapleton was neutral tinted, with light hair and gray eyes, while she was darker than any brunette whom I have seen in England - slim, elegant, and tall.
She 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 her perfect figure and elegant dress she was, indeed, a strange apparition upon a lonely moorland path. Her eyes were on her brother as I turned, and then she quickened her pace towards me. I had raised my hat and was about to make some explanatory remark when her own words turned all my thoughts into a new channel.
`Go back!' she said. `Go straight back to London, instantly.'
I could only stare at her in stupid surprise. Her eyes blazed at me, and she tapped the ground impatiently with her foot.
`Why should I go back?' I asked.
`I cannot explain.' She spoke in a low, eager voice, with a curious lisp in her utterance. `But for God's sake do what I ask you. Go back and never set foot upon the moor again.'
`But I have only just come.'
`Man, man!' she cried. `Can you not tell when a warning is for your own good? Go back to London! Start to-night! Get away from this place at all costs! Hush, my brother is coming! Not a word of what I have said.
Would you mind getting that orchid for me among the mare's-tails yonder?
