"That cannot be done," was the African's reply. "The swamps where the sleeping death (the sleeping sickness) lies are all about it. Only by way of the Tunnel of the Roaring Waters can you escape."
"There is one other way," began Aga, "but that lies through the forest."
"We will take it rather than risk navigation in such a torrent as you describe," decided Billy after the remark of Aga had been translated to him.
But before the two savages could say more there came a distant booming borne down the rocky tube of the corridor.
It was the far-off confused sound of excited voices.
"Quick! glass-eyes, your escape has been discovered; you haven't a moment to lose!" cried Umbashi.
It was only too evident that he spoke the truth. The roar of the searchers' angry voices was rapidly ringing louder.
"Take this, white boys, and defend yourselves to the death rather than be recaptured," said their friend as he thrust a stone knife into Billy's hand.
The old man and Lathrop were already half-away down the swaying ladder.
"Be careful, for the river is swollen with the melting snows of the mountains and runs as if a million demons were in its soul to-night," warned Umbashi.