de of five minutes, with the new plugs in place,
the motor was running better than before.

"Now for home!" cried Tom, "and if I meet Andy Foger I'll race him
this time."

But the RED STREAK was not in sight, and, a little later, Tom had run
the ARROW into the boathouse, locked the door and was on his way up to
the mansion.

"I suppose Mrs. Baggert and Garret will be surprised to see me," he
remarked. "Maybe they'll think we don't trust them, by coming back in
this fashion to see that everything is safe. But then, I suppose, dad
is naturally nervous about some of his valuable machinery and
inventions. I think I'll find everything all right, though."

As Tom went up the main path and swung off to a side one, which was a
short cut to the house, he saw in the dusk, for it was now early
evening, a movement in the bushes that lined the walk.

"Hello, Garret!" exclaimed the lad, taking it for granted it was the
engineer employed by Mr. Swift.

There was no reply, and Tom, with a sudden suspicion, sprang toward the
bushes. The shrubbery was more violently agitated and, as the lad
reached the screen of foliage, he saw a man spring up from the ground
and take to his heels.

"Here! Who are you? What do you want?" yelled Tom.

Hardly had he spoken when from behind a big apple tree another man
sprung. It was light enough so that the lad could see his face, and a
glimpse of it caused him to cry out:

"Happy Harry, the tramp!"

Before he could call again the two men had disappeared.

CHAPTER XIII

TOM IN DANGER

"Garret! Garret Jackson!" cried Tom as he struggled through the hedge
of bushes and ran after the men. "Where are you, Garret? Come on and
help me chase these men!"

But there came no answer to Tom's hail. He could not hear the sound of
the retreating footsteps of the men now and concluded that they had
made their escape. Still he would not give up, but dashed on, slipping
and stumbling, now and then colliding with a tree.

"What can they be doing here?" thought Tom in great anxiety. "Are they
after some more of dad's inventions because they didn't get his turbine
motor?"

"Hello! Who's there? Who are you?" called a voice suddenly.

"Oh, Garret! Where have you been?" asked the young inventor,
recognizing the tones of his father's keeper. "I've been calling you.
Some of those scoundrels are around again!"

"Why if it isn't Tom!" ejaculated the engineer. "However in the world