"And do you mean to say that you waited here o' your ain free will as prisoners?" snorted Mackay.
"For the first little while we were interested to know what sort of country we had reached, and then, when even the riches of the valley began to pall on us, we suddenly realized that we could not help ourselves. The tunnel was always well watched, but even had we got safely through the mountain, where were we then? On the edge of an enormous desert without food or means of transport. You must recollect, Jim, that the camels had been killed, as probably yours have been by this time."
Mackay started to his feet, but resumed his seat with a smile.
"It would be dark before they could venture out," he said, musingly. "We have a good ten hours' grace yet. Hurry up wi' your story, Dick; I want to know whether we should stay here, an' get rich quick wi' the gold oot o' the mountain, or clear out while we have a chance."
"You forget, Jim," said Bentley, quietly, "that your chance has gone. I tried to warn you from the summit in every conceivable manner, but you wouldn't understand. I even scribbled charcoal messages on pieces of wood and threw them down, and you paid no attention."
"We thought you were throwing stones at us," said Bob. "You looked so very like a native at that distance."
"It was a miracle we didn't pop you over with our rifles," commented Emu Bill, shortly.
"I dinna see that our chance has vanished just yet, if we care to take it," Mackay observed, with undiminished assurance. "But go on wi' your yarn, Dick; what I'm anxious to know is, who made that tunnel and for what purpose?"
"First of all, let me tell you," said Bentley, "that this valley is almost impregnable from every direction but one. Away to the north-east there is a slight break in the circular range, but the country in that quarter is so broken and desolate that it is almost impassable, and certainly no explorer making an east or west course would dream of altering his route to the south at that point. He would rather give the mountain—if he happened to see it then—as wide a berth as possible. On the west, as you know, Nature guards her secret very effectually, and it might have remained undiscovered for another hundred years if you had not escaped from the expedition as you did, and so been able to track up the mysterious mountain afresh, and with greater caution. But now that you are here, you may take it as a surety that you will never be allowed to leave with the knowledge you have gained. The fact is, boys, this valley in the heart of the Never Never land is a perfect treasure-house of gold and gems, and it is inhabited by the remnants of a once truly remarkable tribe. They are still infinitely superior in knowledge and intellect to any other aboriginal race that I know, but they have been degenerating slowly these last many centuries, ever since the upheaval, I should imagine, which altered the aspect of Central Australia, and separated it from Polynesia. Their environment has protected them to an enormous degree, for their home in this natural paradise is surely all that could be desired, but, from what I have been able to gather from the king, they have inherited a policy of isolation, which is now almost a part of their creed. Any unsuspecting tribe that wanders near is attacked with the utmost ferocity, as I have myself witnessed on more than one occasion. The early rulers of this strange little kingdom were undoubtedly wise men, and it seems to me they were struggling towards a kind of civilization. The tunnel was driven in their time, but whether it was intended to provide a means of exterminating their savage neighbours of the plains, or gradually pushed through in the course of their excavations for gold, I haven't been able to discover, though I rather fancy both reasons came into play. The gold has been used for all sorts of purposes, because it can be hammered into any shape so very easily. Its value in the outside world is wholly incomprehensible to them."
"Do you think they have ever heard of the great world beyond the desert?" asked Bob, who had been listening with keen interest.