Two minutes of work sufficed. The stone fell inward, and we shouted with
delight when we saw a yawning black hole before us, large enough for two
stooping men to walk abreast. Captain Rudstone hurried upstairs with the
glad news, and meanwhile Menzies and I ventured some distance into the
passage, finding the air sweet and pure.

When we returned to the mouth all of our little party were assembled in
the cellar, each man--and the women as well--carrying a pair of
snowshoes. Flora and Mrs. Menzies were protected against the bitter
weather by furred cloaks. Of the five wounded men one had died within
the hour; the other four were able to hobble along temporarily with some
assistance. For transporting these when we were safely away from the
fort we had two sledges, not counting the one laden with food supplies.

As yet the redskins did not suspect that they were in danger of being
cheated of their triumph; we could hear their frenzied cries faintly.
Overhead the flames were roaring and hissing, and the cellar itself was
hazy with pungent smoke.

CHAPTER XXX.

A STRANGE DISCOVERY.

"All ready?" exclaimed Menzies. "Then forward. If no mishap occurs we
shall be miles away before our escape is discovered."

He entered the passage first, flashing the lantern in front of him, and
the others followed in double file. Captain Rudstone and I, who came
last, took the precaution to replace the slab of stone as we had found
it.

It was a strange experience to thread that underground corridor, built
with herculean toil, when the fort was reared, for just such an
emergency as it was serving now. We had to stoop low to avoid the
raftered roof. The air was close, and not a sound reached us from
outside. We groped along in semi-darkness for the lantern cast no light
behind. It gave one a ghastly oppressive feeling of being buried alive.

The tunnel seemed longer than it really was. We were certain over and
over again that we had passed under the fort yard and the outer
clearing, yet still we went on. But at last Menzies stopped, and called
in a low voice that he had come to the end. Captain Rudstone and I made
our way up to him, and saw that further progress was barred by a slab of
rock that fitted exactly across the passage.

"It will yield with a hard push," said Menzies.

"Wait!" said I. "Let us first blow out the lantern."

This was done, and the three of us put