ould be sought out and destroyed long before we could bring it into
action.

That this was Tao's stronghold, and not the Lone City, now became evident.
I could readily understand why he had retreated here. Fully four times as
many projectors as he had in operation in the Lone City were now in
evidence. Those of shorter range, and spreading rays, kept the entire
country bathed in steady light for several miles around him, while the
larger ones--a hundred of them possibly--roved constantly over the black
emptiness beyond.

From our encampment we could advance but little farther. Fortunately,
retreat was open to us; and once beyond the circle of steady light, we had
no difficulty in moving about in the darkness, even though momentarily we
frequently were within range of the single light-beams, had they chanced
to swing upon us.

This was the situation which, even Mercer agreed, appeared hopeless. We
explored the brink of the precipice below which lay the sea. It was a
sheer drop of many thousand feet. Although a descent might have been made
closer to the Dark City, certainly it was not possible at any point we
could reach. We sent our girls down, and they reported that from below it
appeared probable that access to the ocean was had by the Dark City some
miles farther along. They went but a short distance, for Tao's lights were
occasionally sweeping about; and more than that, they could make but very
short flights, owing to the cold.

To starve Tao out appeared equally as impractical as a direct attack. With
our little army we could not surround the city on a circumference of some
eighty miles. We might, indeed, have barred the several roads that entered
it, but it seemed probable that if Tao wanted to come out he would come,
for all we could do to stop him. And yet to starve him out seemed our only
possible plan.

"We'll have to send back for reenforcements," I told Mercer, Miela and
Anina at one of our many conferences. "An army of several thousand, if we
can maintain it up here."

And then, the very next day, Mercer and Anina came forward with their
discovery. We had set up our encampment of little black fabric tents in a
ravine some six miles outside the city, securely hidden by surrounding
cliffs. Above us across the black sky the greenish-red beams of Tao's
light-rays swept continually to and fro. Miela and I were sitting together
disconsolately in our tent, reviewing the situation, when Mercer and Anina
burst