ire to hang about the fateful rock, and
Hilderman for his part seemed to have no faith in the idea at all. I
fancy he thought it would make no difference to us in what part of the
river we might be, only provided we didn't fall in. So Dennis led the
way back, and he was the first to pick his way to the middle of the
stream. Hilderman and I were some distance behind. Suddenly we stopped
stock-still, and looked at him. He had begun to cough and splutter,
and he seemed rooted to the small stone he was standing on in the
middle of the stream. In a flash I understood, and with a cry I
bounded after him, Hilderman following at my heels.

"It's all right, Ewart," cried Hilderman behind me. "He's only choked,
or something of that sort. He'll be all right in a minute."

Dennis had crossed to the centre of the stream by a way of his own,
and we ran down to the stepping-stones by which we had come, in order
to save the time which we should have been compelled to waste in
feeling for a foothold as we went. Every second was of importance, and
I fully expected to see Dennis topple unconscious into the pool below
before I should be able to save him. I knew what it was exactly; he
was going through my own horrible experience of "drowning on dry
land," to quote Garnesk's vigorous phrase. Imagine my astonishment,
therefore, when I reached Dennis's side with only a slight difficulty
in breathing. There was no sign, or at least very little, of the air
which was "heavier than water." Hilderman plunged along behind me,
and we reached the stone on which my friend was standing almost
simultaneously. Dennis held an arm pointing up the river, his face
transfixed with an expression of horrified amazement. Suddenly
Hilderman gave a hoarse, shrill shout, breaking almost into a scream.

"Shut your eyes!" he yelled. "Shut your eyes! Oh, for heaven's sake,
shut your eyes!"

But I never thought of following his advice. Dennis's immovable arm,
pointing like an inanimate signpost up the river, fascinated me.
Slowly I raised my eyes in that direction. Then I stepped back with a
startled cry, lost my footing, slipped, and fell on my face among the
rocks.

_The river had disappeared!_

CHAPTER XV.

CONCERNS AN ILLUSTRATED PAPER.

The river had disappeared!

In front of us was a great green wall of solid rock, which seemed to
tower into the sky above us, and to stretch away for miles to right
and left. The curious part about it was that t