not conceal
its charms. A halo of glorious golden hair surmounted a head that was
poised expectantly alert above the perfectly rounded shoulders. The
exquisite oval of her face was chiseled in features of transcendent
loveliness. She spoke, and, at sound of her musical voice, Frank and
Tommy were enslaved.

* * * * *

"Gentlemen of the upper world," she said gently, "you are welcome to
Theros. Your innermost thoughts have been recorded by our scientists
and found good. With a definite purpose in mind, you learned of the
existence of the silver dome of Theros, yet you came without greed or
malice and we have taken you in to enlighten you on the many questions
that are in your minds and to return you to mankind with a knowledge
of Theros--which you must keep secret. You are about to delve into a
mystery of the ages; to see and learn many things that are beyond the
ken of your kind. It is a privilege never before accorded to beings
from above."

"We thank you, oh, Queen," spoke Frank humbly, his eyes rivetted to
the gaze of those violet orbs that seemed to see into his very soul.
Tommy mumbled some commonplace.

"Orrin--the sphere!" Phaestra, slightly embarrassed by Frank's stare,
clapped her hands.

At her command, Orrin, who had stood quietly by, stepped to the wall
and manipulated some mechanism that was hidden by the hangings. There
was a musical purr from beneath the floor, and, through a circular
opening which appeared as if by magic, there rose a crystal sphere of
some four feet in diameter. Slowly it rose until it reached the level
of their eyes and there it came to rest. The empress raised her hands
as if in invocation and the soft glow of the lights died down, leaving
them in momentary darkness. There came a slight murmur from the
sphere, and it lighted with the eery green flickerings they had
observed in the dome of silver.

* * * * *

Fascinated by the weaving lights within, they gazed into the depths of
the crystal with awed expectancy. Phaestra spoke.

"Men from the surface," she said, "you, Frank Rowley, and you, Arnold
Thompson, are about to witness the powers of that hemisphere of metal
you were pleased to term 'Silver Dome.' As you rightly surmised, the
dome is of silver--mostly. There are small percentages of platinum,
iridium, and other elements, but it is more than nine-tenths pure
silver. To you of the surface the alloy is highl