ed weary work, for it was only now and then that they could
hear the sound of the hammer, for the current of air seemed to bear it
away; while, when by chance the sounds did reach their ears they were
most tantalising, at one time seeming very near, and at others so faint
that they felt that the work going on must be very distant.

The dog came back with food and lights and stayed with them, now
trotting to the opening to bark at the sounds; and at times standing at
the edge of the lower cavity to bark fiercely at those from below, his
ears and the thick wolf frill about his neck being blown about by the
fierce current of air.

And so the time went on, first one and then the other descending to find
that the water was steadily rising, and after each examination there was
a thrill of dread as the looker-on asked himself, Would they win the
race?

How long was it? Was it night, now, or day?

Questions, these, which they could not answer, and at last, with their
miserable state of despondency increasing, they lay half-stupefied,
listening for the help which, as the hours wore slowly by, seemed as if
it would never come.

The end was unexpected when it did arrive, after what, in its long-drawn
agony, seemed like a week. Gwyn had sent a message by the dog imploring
for news, for he said the water was very close to them now, as it was
lapping the top of the cavity, and every now and then brimming over and
slowly filling the bottom of the sloping cavern.

All at once, heard plainly above the rush of the air and apparently
close at hand, there was the loud striking of hammers upon stone.

Gwyn thrust his head into the opening at once, and shouted, his heart
bounding as a hollow-sounding cheer came back from just the other side
of the wedge.

"Who is it?" cried Gwyn, with the despondency which had chilled him
taking flight.

"Vores," came back. Then--"Look here, sir! I can't break through this
stone. I've no room to move and strike a blow. How far can you get
away from it?"

"About sixty feet," said Gwyn, after a few moments' thought.

"Any place where you can shelter from flying stones?"

"Oh, yes, several."

"Then I'm going back for a cartridge, and I shall put it under the
stone, light a slow fuse and get away. It must be blasted."

"But you'll blow the roof down and stop the way."

"No fear of that, sir. If I do, it will only be in pieces that we can
get rid of this end, you that. It must be done,