Dr. Gladby to come over and see dad. But now I want to find out who that
was under this window."

Once more Tom looked out. The moon had emerged from behind a thin bank
of clouds, and gave a little light.

"See anything?" asked Mr. Gunmore cautiously.

"No," whispered the youth, for it being a warm might, the windows were
open top and bottom, a screen on the outside keeping out mosquitoes and
other insects. "I can't see a thing," went on Tom, "but I'm sure--"

He paused suddenly. As he spoke there sounded a rustling in the
shrubbery a little distance from the window.

"There's something!" exclaimed Mr. Gunmore.

"I see!" answered the young inventor.

Without another word he softly opened the screen, and then, stooping
down to get under the lower sash (for the windows in the library ran all
the way to the floor), Tom dropped out of the casement upon the thick
grass.

As he did so he was aware of a further movement in the bushes. They were
violently agitated, and a second later a dark object sprang from them
and sprinted along the path.

"Here! Who are you? Hold on!" cried the young inventor.