"Do you suffer great pain?" asked Fernando, speaking tenderly, as he approached the fissure on tiptoe.
"Give me your hand," came the answer in a weak, breathless voice.
Instead of a hand, suddenly Fernando thrust his rifle through the opening and fired. The loud report echoed in the shallow vault. A strong smell of cordite was driven to their nostrils.
Without, there was a shriek. Harry rushed to the opening and looked through. He saw a white figure flying in the moonlight like a ghost. Fernando—the half-bred Spaniard—threw back his head and laughed the laugh of a fiend.
"What does all this mean?" cried Braid, turning fiercely upon the man.
"That was no more my brother," said the guide, "than the dog-fox is brother to the eagle. That man was the sheikh—the Black Dog himself."
"It was your brother's voice," said Harry.
"Indeed!" said the man. "I should know my brother's voice. I tell you once again my brother is dead. The Black Dog slew him; and then, recognizing the man he had killed, he guessed that I, too, was with you, and he came here to kill me, imitating my brother's voice, practising the cunning which has made him feared from the Niger to the Congo. And he has gone with a bullet in his chest."
"You did not kill him?" asked Braid.
"No. He fled, realizing that his trick had failed. But because he killed my brother, Cortes, whom I love, I swear now by the saints that I will avenge my brother's death, that I will send the Black Dog to the shades. Henceforward it is his rifle against mine, his treachery against my wits; it is the fox against the serpent."