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.