y at the very instant that my foot was
poised above his head, over which I must step.

Breathlessly I waited, balancing upon one foot, for I did not dare
move a muscle. In my right hand was my keen short-sword, the point
hovering an inch above the thick fur beneath which beat the savage
heart.

Finally the apt relaxed, sighing, as with the passing of a bad dream,
and resumed the regular respiration of deep slumber. I planted my
raised foot beyond the fierce head and an instant later had stepped
over the beast.

Thuvan Dihn followed directly after me, and another moment found
us at the further door, undetected.

The Carrion Caves consist of a series of twenty-seven connecting
chambers, and present the appearance of having been eroded by
running water in some far-gone age when a mighty river found its
way to the south through this single breach in the barrier of rock
and ice that hems the country of the pole.

Thuvan Dihn and I traversed the remaining nineteen caverns without
adventure or mishap.

We were afterward to learn that but once a month is it possible to
find all the apts of the Carrion Caves in a single chamber.

At other times they roam singly or in pairs in and out of the
caves, so that it would have been practically impossible for two
men to have passed through the entire twenty-seven chambers without
encountering an apt in nearly every one of them. Once a month
they sleep for a full day, and it was our good fortune to stumble
by accident upon one of these occasions.

Beyond the last cave we emerged into a desolate country of snow
and ice, but found a well-marked trail leading north. The way was
boulder-strewn, as had been that south of the barrier, so that we
could see but a short distance ahead of us at any time.

After a couple of hours we passed round a huge boulder to come to
a steep declivity leading down into a valley.

Directly before us we saw a half dozen men--fierce, black-bearded
fellows, with skins the color of a ripe lemon.

"The yellow men of Barsoom!" ejaculated Thuvan Dihn, as though
even now that he saw them he found it scarce possible to believe
that the very race we expected to find hidden in this remote and
inaccessible land did really exist.

We withdrew behind an adjacent boulder to watch the actions of
the little party, which stood huddled at the foot of another huge
rock, their backs toward us.

One of them was peering round the edge of the granite mass as though