There was his rifle, lying on the ground, with no sign of an empty cartridge to show that the weapon had been discharged. Andy removed the magazine and found that the cartridges were still intact.

"I can't understand it," he exclaimed. "The pater was evidently in a hurry, for, you see, the rifle was not placed against a rock, but was thrown down on the ground. He's too careful, in ordinary circ.u.mstances, to do a thing like that."

"Well, where is he? If Blight had managed to get the better of him he would have taken away the rifle."

"He may have chased him right across this island. Come on, it's no use wasting time here; let's try and pick up the trail."

Andy leapt upon the flat top of the rock and a.s.sisted his chum to follow his example. Both took it for granted that there was no further need for concealment.

From where they stood the ground had the appearance of a broad belt of flat rock, divided in all directions by narrow crevices, most of which could be jumped across with the greatest ease, while ahead was the first of a series of cliffs, which incircled the base of the peak of the island.

"Look!" exclaimed Ellerton, pointing to a little heap of brown canvas which was lying on the rock about thirty feet away. "There's your father's haversack."

The lad was right, for Mr. McKay had discarded the article as he commenced the pursuit of the fugitive. From this spot the mingled tracks of the hunter and the hunted were easily traced, by reason of the deposit of lava dust, which grew thicker as the lads advanced.

Suddenly they came to an abrupt halt. Almost at their feet began the treacherous slope, ending in the horrible fissure which had been the cause of Blight's death and Mr. McKay's disaster.

Although the still sliding dust and sand had almost hidden the traces of Mr. McKay's desperate struggle to save himself from the yawning pit, there remained sufficient evidences of the disappearance of the fugitive and his pursuer.

The faces of both lads grew pale. Andy was about to rush towards the brink of the abyss when Ellerton's detaining hand was laid upon his shoulder.

"It's nothing more or less than a trap," said he. "You'll----"

The sentence remained unfinished, for from the depths of the chasm a hollow voice that the lads hardly recognised as Mr. McKay's repeated the warning:

"Stand back, lads!"

"Are you all right, sir?" shouted Ellerton.

"Yes, but you cannot get to my aid without a rope. Hurry back to the house, and bring all hands with you. A lantern will also be useful.

Be as quick as you can, for it's pretty doleful down here."

"All right, sir, we'll make haste; but stand by!"

And as a parting gift Ellerton dexterously threw Mr. McKay's haversack, still containing an ample supply of food, into the pit.

Andy, however, hesitated.

"Are you sure you are all right, dad?"

"Ay, my boy. Why do you ask?"

"Because your voice sounds so strange. I suppose it's the rocks that affect it. How far did you fall?"

"I hardly know; about thirty feet, I expect; luckily the ground's soft."

"Seen anything of Blight?"

"Dead!" replied Mr. McKay.

With the utmost despatch Ellerton and Andy returned to the house, where, having told the others all they knew about the accident, they collected a couple of coils of rope, some lanterns, two strong crowbars, a hammer, and, at Ellerton's suggestion, two six-inch pulleys.

The four lads--for even Quexo insisted on coming, though he was still in a weak state of health--set off for the scene of the disaster, Andy and Terence carrying the bulk of the appliances, while Ellerton and the mulatto took only what they could place in their belts.

Cheering up the prisoner with a l.u.s.ty shout of encouragement, the rescuers proceeded to drive the crowbars into a convenient crevice in the rocks, so that one was about ten feet nearer to the chasm than the other.

From the base of the outside bar to the top of the inner one, Ellerton lashed a piece of rope, then making sure that the "crows" would bear any strain that was likely to be put upon them, he attached a pulley to the base of the innermost.

Through the block was rove one of the coils of rope, one end of which he tied round his waist. Then, taking the lighted lantern in his hand, he walked cautiously towards the brink of the pit, the others paying out the rope as he went.

Before he had gone a distance of five yards the pumice dust began to slide away from under his feet, causing him to sit down on the slope, while the avalanche nearly blinded Mr. McKay as he was looking upwards for the expected relief.

"Come back, Hoppy!" shouted Andy. "Remember your arm."

"I do," replied Ellerton with a laugh. "It's giving me good cause to remember it, but I mean to make the best of it. You fellows can do more good by hauling on that rope than I can, so slack away."

Terence and Andy accordingly "slacked away," and Ellerton slid another yard or so towards the brink. He was then able to lower the lantern to Mr. McKay, and at the same time he made the discovery that the shaft was too rugged to allow a man to be hauled up by a rope without serious danger of the rope being chafed through by the sharp projections.

He explained the situation to Mr. McKay, who fully realised the force of his remarks.

"Never mind, we'll manage it right enough," concluded Ellerton cheerily, and giving the word he was hauled back to where his companions stood.

"We must have one of those trees down," he said, pointing to the distant palms.

Accordingly the lads set off for the forest, where without much difficulty a stout trunk, thirty feet in length, was felled. The work of transporting it to the brink of the pit was a more tedious business, and an hour elapsed ere they succeeded in slinging the timber across the yawning gulf, where it rested with about ten feet imbedded in the soft lava on either side of the hole.

"Now you can do this part of the work better than I," said Ellerton to Andy. "Lash this block to the centre of the trunk, and reeve a rope through it."

This Andy managed to do. He also lashed a smaller piece of timber at a distance of about four feet below the tree-trunk, so as to form a platform to enable Mr. McKay to obtain a clear spring when hauled up as far as the pulley would permit.

"All ready, pater?" asked the son.

"Wait a moment, Andy. Could you manage to come down here, do you think?"

"I'll try. I say, you fellows, I'm going down, so pay out the rope."

Andy swung himself from the main beam upon the lower piece of timber, and, summoning up his courage, launched himself off from the swaying perch.

Slowly he descended, spinning round on the straining rope like a joint on a meat-jack, while at almost every second his shoulders or hips came into contact with the jagged walls of the shaft. To avoid the dust he kept his head bent downwards, and as he did so he saw the glimmer of the lantern from beneath.

"Thirty feet, do you call it?" he asked, as his feet touched the floor of the pit, and his father grasped his hand. "It's sixty at the very least."

"I don't think so," was the reply. "You see, looking down from a height the distance always appears greater. Had the floor been hard rock, I should have been killed or at least seriously injured. But to change the subject, look here."

Mr. McKay had, during the long interval of waiting since Ellerton had lowered the lantern, made another tour of exploration, and now he led the way towards the tunnel where he had found an old musket.

He had made a strange discovery. At no very distant date a long cavern of varying height and breadth existed here. Where its entrance was Mr.

McKay had not found out; but a volcanic disturbance had caused a mighty fissure to divide the original cave in two, as an examination of the strata prove conclusively.