ation as if his breath was being sucked away, then a deafening roar,
followed by a crash.

Again they had to wait till the fumes had somewhat dispersed. Then,
with Sir Edward and Mark leading, they returned, expecting to see the
wall demolished; but as far as they could see it was perfectly sound,
while another huge mass from the roof had come down, to lie piled up
before it, so that there was hardly room for a man to crawl over the
heap, so close was it to the roof.

"It's of no use, Mark," whispered Sir Edward, as they drew back a little
from the smoke, "we must devise some other plan. It is useless to try
another bag there without first clearing away the mass of stones, and we
can only do that at the expense of many men wounded by pike-thrusts,
perhaps killed."

"Yes," said Mark, "and it doesn't seem fair to order them to do it."

"I cannot, my boy. There, we have done our work for this time. Let's
get out of this horrible smoke."

"Hoi, you!" came from beyond the wall; "if you fire any more of that
choke-dog stuff, I'll give orders to my men to kill the prisoners,
'specially the girl."

"You cowardly ruffian!" cried Mark, in a rage.

"Bah! Puppy!" came back scornfully.

"Don't answer, boy," said Sir Edward softly.

"But father!--if--"

"It is only a boast. They dare not do such a thing as that. Come."

They retired, making for the mouth of the cavern, where the cool night
air blew with refreshing force.

"But we cannot give up, father," cried Mark.

"I am not going to give up, my boy," said Sir Edward quietly. "When an
assault upon a stronghold fails, a general tries to starve his enemy
into submission. We must do the same here. Unfortunately they must
have stores, and they have a good supply of water from a spring within
there. But still we must try. The first thing is to protect ourselves
from a sudden attack, and this will be easy. Now, my lads, every man
take in a block of stone, and carry it into the cavern as far as the end
of the first chamber. Take these from the breastwork; we do not want it
now, for we shall encamp inside."

Mark nodded approval, and the men, glad that the night's fighting was at
an end, set to work with a will, after laying their arms aside; and in
less than an hour had walled up to a great thickness the narrow exit
from the cavern, wedging in the top stones with blows, and in spite of
the want of mortar producing a good solid piece of work, through which
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