No sooner had Brent shut the door, however, than it seemed as if the
very face of the outer rocky wall of the cavern began to move--to tilt,
as if on hinges.

If a human eye had been in the Graveyard of Genius at that instant it
would have sworn that it perceived in the inky blackness of the tilting
rock a passage, and in the shadows of that passage a huge, weird,
grotesque figure peering in.

Then the tilting rock door closed again, as the figure disappeared down
the rocky passage on the opposite side--a menace and a threat to the
owner of Brent Rock, insecure even in his millions.



CHAPTER II


When Brent arrived back at the library he had quite recovered his poise,
at least to the eyes of those in the library. Zita had joined Eva with
the old inventor, Davis.

As Brent entered, Davis uttered an exclamation of joy at the sight of
his motor. For the moment Brent almost glowed.

"Along with your invention," he beamed, as he handed the model to the
old man, "I am going to release many others to the world."

All this not only Locke was noting, but Zita, too, appeared to be an