are known to exist, and those were worn as the insignia of their rank and position by the two old men in whose charge was placed the operation of the great engines which pump the artificial atmosphere to all parts of Mars from the huge atmosphere plant, the secret to whose mighty portals placed in my possession the ability to save from immediate extinction the life of a whole world.
The stone worn by the thern who confronted us was of about the same size as that which I had seen before; an inch in diameter I should say. It scintillated nine different and distinct rays; the seven primary colors of our earthly prism and the two rays which are unknown upon Earth, but whose wondrous beauty is indescribable.
As the thern saw us his eyes narrowed to two nasty slits.
"Stop!" he cried. "What means this, Thuvia?"
For answer the girl raised her revolver and fired point-blank at him. Without a sound he sank to the earth, dead.
"Beast!" she hissed. "After all these years I am at last revenged."
Then as she turned toward me, evidently with a word of explanation on her lips, her eyes suddenly widened as they rested upon me, and with a little exclamation she started toward me.
"O Prince," she cried, "Fate is indeed kind to us. The way is still difficult, but through this vile thing
