Thus ran his plans as, day after day, he pressed farther into the heart of the unknown country that the British had abandoned in despair over three years before. They found it deserted, in some parts almost impenetrable, so dense was the growth of bush in all directions. And yet there were times when it seemed to Herne that the sense of emptiness was but a superficial impression, as if unseen eyes watched them on that journey of endless monotony, as if the very camels knew of a lurking espionage, and sneered at their riders' ignorance.
This feeling came to him generally at night, when he had partially assuaged the torment of thirst that gave him no peace by day, and his mind was more at leisure for speculation. At such times, lying apart from his companions, wrapt in the immense silence of the African night, the conviction would rise up within him that every inch of their progress through that land of mystery was marked by a close observation, that even as he lay he was under _surveillance_, that the dense obscurity of the bush all about him was peopled by stealthy watchers whose vigilance was never relaxed.
He mentioned his suspicion once to Hassan; but the Arab only smiled.
"The desert never sleeps, _effendi_. The very grass of the _savannah_ has ears."
It was not a very satisfactory explanation, but Herne accepted it. He put down his uneasiness to the restlessness of nerves that were ever on the alert, and determined to ignore it. But it pursued him, none the less; and coupled with it was the voice that called to him perpetually, like the crying of a lost soul.
They were drawing nearer to the mountains when one day the Arab lad, Ahmed, disappeared. It happened during the midday halt, when the rest of the party were drowsing. No one knew when he went or how, but he vanished as if a hand had plucked him off the face of the earth. It seemed unlikely that he would have wandered into the bush, but this was the only conclusion that they could come to; and they spent the rest of the day in fruitless searching.
Herne slept not at all that night. The place seemed to be alive with ghostly whisperings, and he could not bring himself to rest. He spent the long hours revolver in hand, waiting with a dogged patience for the dawn.