"Have you been here all the while?"

"All but jes' a few minutes, when I went to de barn to put some liniment
on Boomerang's So' foot."

"H'm! Some one might have slipped in here while I was away," mused Tom.
"I ought to have locked the doors, but I was in a hurry. This thing is
getting on my nerves. I wonder if it's Andy Foger, or some one else, who
is after my secret?"

He made a hasty examination of the shop, but could discover nothing more
wrong, except that one of the planes of the Humming-Bird had been
shifted.

"It looks as if they were trying to see how it was fastened on, and how
it worked," mused Tom. "But my plans haven't been touched, and no damage
has been done. Only I don't like to think that people have been in here.
They may have stolen some of my ideas. I must keep this place locked
night and day after this."

Tom spent a busy week in making improvements on his craft. Mr. Swift was
doing well, and after a consultation by Dr. Kurtz and Dr. Gladby it was
decided to adopt a new style of treatment. In the meanwhile, Mr. Swift
kept his promise, and did no work. He sat in his easy-chair, out in the
garden, and dozed away, while Tom visited him frequently to see if he
needed anything.

"Poor old dad!" mused the young inventor. "I hope he is well enough to
come and see me try for the ten-thousand-dollar prize--and win it! I
hope I do; but if some one builds, from my stolen plans, a machine on