wren made the air
sweet above him, while the morning sun began to wink and blink against
the shadows which still lay against the face of the guardian cliffs.
Kirby glanced at his watch and got up.

Crossing beyond the mouth of the geyser, he grinned good morning at his
friend the Conquistadore, and marched on into the shade of the live oak
which grew nearest the geyser. Here he made one end of his rope fast to
the gnarled trunk, inspected his pistol, patted his tunic to make sure
that the cylinder of gold was safe, then stood by to await the geyser.

With the passing of three minutes there came from the still empty
orifice a sonorous rumbling. Kirby grinned.

From deep in the earth issued a sound of fizzing and bubbling, and
then, to the accompaniment of subterranean thunder, burst loose the
milky, upward column which had never ceased to awe the man who watched
so eagerly this morning. As the titanic jet leaped skyward now, the
slanting rays of the sun caught it, and turned the water, fanning out,
into a fire opal, into a sheet of living color.

Kirby, hard headed to the last, drew from the supply in one pocket of
his tunic, a strip of one of the tuberlike roots, and munched it.

The thunder ceased. The waters receded.

After that Kirby hesitated not a second. Promptly he moved forward,
flung his coil of line down into the geyser tunnel, and swung on to the
line. By the time he had swallowed the last bite of his breakfast, the
world he knew had been left behind, and he was climbing down to a new.

* * * * *

It became at once apparent that the gorgeously colored, glassy-smooth
throat glowed with tints which were unfamiliar to him. He could perceive
these new shades of color, yet had no name for them.

As he stopped after fifty feet to breathe, the color phenomenon made him
wonder if the tuber roots he had been eating had affected his vision;
then decided they had not. In addition to food value, the roots had some
power to stimulate courage and a slight mental exhilaration. But the
drug had proved non-habit forming, and Kirby knew that his powers of
perception were not now, and never had been, affected.

He swung down further.

Just a moment after he begin that progress was when things began to
happen to him. First he heard what seemed to be the low titter of a
human voice laughing sweetly. Next came a far off, unutterably lovely
strumming of music. And then he realized that, a