He listened, with every nerve on the strain, but there was no sound; and after crouching low, perfectly still for some minutes, he felt convinced that it was his own act: the twig had caught a leaf, been held by for a minute or so, and then released.

“I wish I was not such a coward,” thought Nic, as he once more started off, satisfied now that he was close at hand, for he could just see the piled-up rocks from beneath which the spring bubbled out.

And now, as more cautiously than ever he crept on, so as to get within springing distance of the hole, he began to think of the long, deep, cool drink in which he would indulge—for his throat felt dry, and he was suffering from a parching, burning thirst.

Closer and closer and closer he crawled, now on hands and knees, with his gun slung over his back—so near that he had but to spring up and take a few steps to be there, but holding back so as to preserve the greatest caution to the very last.

In this way he reached to within five yards of the hole,—stretched out a hand to press aside a frond of fern, and gave one good look round.

He did so, and held on as if paralysed, feeling as if he were dreaming of being back on board the Northumbrian on his voyage out, and watching the convicts having their daily airing.

For there, just in front of him, and one on either side of the hole, half hidden by clumps of fern, crouched, like a couple of terriers watching a rat-hole, two of the convicts whom he had forgotten, but whose features and peculiarities were once more filling his brain.

Yes, there they were; he did not remember their numbers, but their features were clear enough: those of the pitiful, hang-dog, pleading-looking convict, whom he had set down as a sneak; and the good-humoured, snub-nosed, common scoundrel who had amused himself by making grimaces whenever he encountered his eye.

But that which startled Nic the most was the fact that they were inimical to the tenant of the cavern, for, as they watched so intently that they had not heard the boy’s approach, each man held a native war club or nulla-nulla—poised ready to strike the poor fellow who raised his head above the edge of the hole, and a blow from one of those clubs meant death.

For some moments Nic felt too much stunned to even think, while the silence and the rigid motionless position of the two men before him added to the idea that it might be after all imagination.