Clearly there were only two courses open.  They must either go back by the path they had entered by—­making up their minds to cross that dizzy ledge in the darkness—­or he would have to leave the boy somewhere while he went for help.  He gave up the latter alternative at once, and set his mind on the first.

“We will rest for an hour,” he said.  “Then we will go down.”

“To look for another way?” asked the boy, wearily.

“Or to follow the track we entered by.”

“I couldn’t,” whispered the boy.

“Then we will try another passage—­the one ‘they’ went down by.  Of course”—­and the Hunter’s voice gained in cheeriness—­“that is our plan, and if we hurry we shall be outside in no time.”

“Very well,” said the boy, jumping up with a sudden flush in his cheeks, showing a return of feverishness.

“Rest awhile, lad; it is morning yet.  See how the sun’s rays slant towards the west.  At noon they will be vertical, and then we shall have the whole afternoon.”

They sat down with their eyes turned up to the specks of blue, and watched the sun-shafts dip from the west towards the centre till they poured their white light straight down.  Then they started for the long downward track, Mr. Hume this time leading the way with his rifle ready.

When they came again to the cavern of the skulls, the Hunter paused before pushing the mat aside.  For some seconds he stood listening; then, cautious still, with the point of his knife he forced apart a couple of the rush strands and peeped through.  The place seemed as it had been, and he was about to step in when he remembered that Venning had placed the skull on the block of stone.  There was the block, but there was no skull upon it.  Standing back, he whispered to Venning to keep where he was; then, with his rifle ready, he quietly moved the mat aside.

There was a howl, as some creature, squatting on the floor, turned a lined and hideous face towards the corner, and then scuttled out of view.  Mr. Hume leapt to the floor, and ran to seize the creature who had taken refuge under a hanging mat.  His hand, however, met with no resistance, and, brushing the mat aside, he saw an opening leading down.

“It went down there,” he said, as Venning, showing a startled face at the opening, called out to know what had happened.

Venning jumped down, and looked into the new outlet.  “Let us follow,” he said eagerly.

Mr. Hume shook his head.  “We know one has gone.  There are probably others; and we don’t know that it would lead us out.  The other way would.”

“It makes me ill to think of the other way,” said Venning, vehemently.

“It looks like a rabbit-hole.”

“I’ll go first.”

“It may mean another night, if it takes up much time.”

“I’m sure it’s right,” persisted the boy.

“Very well, here goes;” and the Hunter submitted against his judgment, because he feared beyond anything the breakdown of the boy’s nerves.