bidding, spot.

Below us upon the river's bank the great white apes were devouring the
last remnants of Tars Tarkas' former companions, while great herds of
plant men grazed in ever-widening circles about the sward which they
kept as close clipped as the smoothest of lawns.

Knowing that attack from the tree was now improbable, we determined to
explore the cave, which we had every reason to believe was but a
continuation of the path we had already traversed, leading the gods
alone knew where, but quite evidently away from this valley of grim
ferocity.

As we advanced we found a well-proportioned tunnel cut from the solid
cliff. Its walls rose some twenty feet above the floor, which was
about five feet in width. The roof was arched. We had no means of
making a light, and so groped our way slowly into the ever-increasing
darkness, Tars Tarkas keeping in touch with one wall while I felt along
the other, while, to prevent our wandering into diverging branches and
becoming separated or lost in some intricate and labyrinthine maze, we
clasped hands.

How far we traversed the tunnel in this manner I do not know, but
presently we came to an obstruction which blocked our further progress.
It seemed more like a partition than a sudden ending of the cave, for
it was constructed not of the material of the cliff, but of something
which felt like very hard wood.

Silently I groped over its surface with my hands, and presently was
rewarded by the feel of the button which as commonly denotes a door on
Mars as does a door knob on Earth.

Gently pressing it, I had the satisfaction of feeling the door slowly
give before me, and in another instant we were looking into a dimly
lighted apartment, which, so far as we could see, was unoccupied.

Without more ado I swung the door wide open and, followed by the huge
Thark, stepped into the chamber. As we stood for a moment in silence
gazing about the room a slight noise behind caused me to turn quickly,
when, to my astonishment, I saw the door close with a sharp click as
though by an unseen hand.

Instantly I sprang toward it to wrench it open again, for something in
the uncanny movement of the thing and the tense and almost palpable
silence of the chamber seemed to portend a lurking evil lying hidden in
this rock-bound chamber within the bowels of the Golden Cliffs.

My fingers clawed futilely at the unyielding portal, while my eyes
sought in vain for a duplicate of the button wh