He sprang to his feet, staring about in bewilderment.  The sun was above their heads, red and leaden; all round stretched the scorched scrub; the creek lay to their right but the five trees had vanished, swallowed up in a thick, dun-coloured fog.

“Lord, we’re in for a dust-storm, old lady!”

“Will it hurt us?”

He dilated on the horrors of dust-storms, and how they buried people and choked the water-holes.  It grew dark, not a breath of wind stirred the scrub, not a bird moved or twittered in the few trees fringing the creek.

“It may pass us by,” said Louis.  “They’re often very localized.  But if it gets us, be sure not to speak, or your mouth will be full of dust, and keep your eyes shut tight.”

They plodded on.  Once Marcella started violently as a parakeet flew by with a brilliant flash of pink and green wings and a screaming cry.  They found it difficult to breathe.  It seemed as though all the air had been sucked up behind the advancing wall of dust and sand.  One moment they were walking in clear, though breathless air; the next the storm was upon them, stinging and blinding and burning as the particles of dust were hurled with enormous velocity by the wind.

Marcella gave a little cry of fear, and in the process got her mouth filled with dust as Louis had prophesied.  Groping out blindly she found his hand, and they clung together.  She would have given anything to be able to speak, for the horror of the ancient doom of Lashnagar rose up all round her and gripped her.  But for more than an hour they battled in silence, unable to go either backwards or forwards.  When finally the storm passed over, leaving them with parched throats and red-rimmed, aching eyes and blistered skin, it was dusk—­the swift dusk of the sub-tropics.

Marcella wanted to stay and wash the dust away in the creek; Louis, remembering the food shortage, insisted on pushing on.  But when darkness fell they were going blindly in the direction they guessed to be right for they could see nothing of the five trees.  Louis got depressed.  Marcella felt tired enough to be depressed too, but had to keep his spirits up.  She was just going to suggest that they should give up and rest supperless for the night when they heard a faint “coo-ee,” and even more faintly the plodding sound of a horse’s steps.  Louis excitedly gave an answering shout, and in a few minutes they saw a horse looming through the darkness.

“What a good job I’ve found you,” came a boy’s voice, and they saw a small figure standing beside them, reaching about to the horse’s shoulder.

“Were you looking for us?” said Marcella.  “And are we found?  We don’t seem to be anywhere.”

“I was looking for the sheep.  I came across twenty back there, suffocated with the dust.  I don’t know what he’ll say when he knows!  But it’s a good thing I found you, else you’d have gone on all night.”

He turned then, and they followed him.  He said nothing more until after about two miles of silent tramping they turned the corner of a high fence threaded with wonga-vine, and saw the lights of a homestead.  Marcella felt she understood fire-and sun-worshippers.  She could cheerfully have worshipped the twinkling light.