Bob, too, was much exercised over the prolonged absence of the desert sentinel; it had figured so much in all their calculations that it had, indeed, been the initial quest of the expedition.
"There's an extraordinary heat haze rising up straight ahead," said he. "Perhaps it hides that shadowy mountain."
"It's there right enough," said Mackay, again. "I mind well that I didna see it until I was right up against it."
"There's something mighty uncanny about this place," grunted Never Never Dave, who had been gazing around suspiciously.
A gentle zephyr breeze wafted towards them from the obscuring mists, and they sniffed the air wonderingly.
"Blow me tight, boys," muttered Emu Bill, "we has struck old Jimmy Squarefoot's country."
"That are a fact," concurred Never Never Dave, solemnly; "we has come a bit too far on this trip. No wonder poor ole Bentley didn't get back."
"Why, what is wrong?" asked Jack, in some alarm.
"What is wrong?" echoed Never Never. "Why, we must be near Hades, my lad; don't you smell it?"
A strong odour of a pungent, sulphurous nature assuredly filled the air. Mackay was equally mystified with the others, though he did not give expression to his thoughts. He was trying to recall to the minutest incident the happenings of over a year ago in the same district.