CHAPTER XXI.

CUT OFF FROM THE OUTER WORLD.

The lamp was lit instantly, and without a moment's delay Guy led the
party at full speed down the corridor until the descent was reached.

"Now hurry down, all of you," he cried. "You have a flask of powder
about you, Canaris. Give it to me."

"What are you going to do, Chutney?" asked Melton in alarm.

"Put an end to all pursuit," was the stern reply; and, seizing the
flask, he placed it on the ground, and pouring a little powder on a
strip of linen torn from the lining of his blouse, he deftly rolled a
fuse and inserted one end in the mouth of the flask.

His intentions were apparent. The roof and walls of the passage were of
loose earth and stone. A blast would bring them down in an avalanche.

Canaris attempted to expostulate, but Guy drove them all down the slope
and applied a match to the fuse.

It was high time, for up the passage shone the gleam of torches. The
enemy had effected an entrance.

Guy joined his companions on the shore of the river, and almost
instantly a terrific explosion took place. It seemed to rend the earth.
A tremendous crash and rumbling noise followed, and then all was
quiet.

The concussion put out the lamp, but as soon as it was lighted again Guy
ran up to see the result of his attempt.

No trace of the passageway existed. In its place was a grim wall of
earth.

The full significance of what he had done now flashed into Guy's mind
and he gazed blankly into the faces of his comrades.

"We are buried alive," said Melton bitterly. "We are as dead to the
world as though we were in our coffins."

"We have simply burned our ships behind us, that is all," replied
Chutney. "Now for the river and freedom."

They went back and sat down beside the swiftly-flowing water.

"Bless me if I know whether I am on my head or my feet," said Sir
Arthur. "What on earth does this mean?"

"It means that these brave fellows have saved us from a fate worse than
death," cried the colonel; "that is all I care to know at present."

"I will explain all," said Guy.

He straightway related everything that had happened from the time they
were separated on the way to Harar to the discovery of the underground
river and the daring plan for the rescue of the prisoners.

The colonel could scarcely repress his astonishment as he listened to
the wonderful story, and at its conclusion he embraced his rescuer
warmly.

"We