. I should be able to smash it! I'd like
to see Helen again, though."

He gathered the sheet around him, and began picking a cautious way up
the canyon, staying always in the cover of boulders or brush. A few
times he disturbed a rock, or snapped a twig beneath his foot. Then he
waited out of sight for long minutes, though he had no reason to
believe that the metal monsters were on the alert for him.

"I've got to do it! The world depends on it!" he kept saying again and
again in his mind.

The quick darkness of the tropics had fallen almost before he started.
But he welcomed the night, for, if it made his own silent progress
more difficult, it reduced the hazard that he would be discovered.

Gauging the time by the slow wheeling of the diamond-like stars across
the velvet sky, he thought that two hours had passed when he reached
the head of the canyon. He stood up cautiously to survey the little
plateau at the summit of the hill.

It was several acres in extent, quite level, and almost clear of
vegetation. At the farther side was a pile of wreckage, which, he
supposed, had been the quarters of Dr. Hunter's party, before they had
been destroyed.

Many huge machines stood about the plateau, vast, dark masses looming
in the starlight. Mostly they were either not running or very silent
in operation; but a very deep, vibrant humming sound came from one
near him. Smaller shapes were moving about them, with long easy leaps.
These, he knew, were the mechanical monsters, though it was too dark
to distinguish them.

* * * * *

But by far the most prominent object upon the plateau was the enormous
gleaming thing that Helen had said was the station over which came the
signals from the Master Intelligence on Mars. One of its three towers
sprang up not far from where he stood. The huge, refulgent ring,
swathed in its mist of purple fire, was a full hundred feet above him;
and the slender needle, pulsing with white flame, swinging within and
below the colossal ring, was itself a hundred feet in length.

The white needle, for all its length, seemed hardly thicker than a
man's finger. It was mounted at the top of a curiously complex and
delicate-looking device that spread broadly out between the three
towers, below the center of the huge purple ring.

Dan looked at it and decided that his plan had at least a chance of
success--though he had no hope that it would not be fatal to him.

Quickly