“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 did you get here?  I thought you were at Sandport.”

“I’ll explain later, Garret.  Just now I want to catch those men, if I can.”

“Which men?”

“Happy Harry and another one.  I saw them hiding down by the orchard path.  Come on, they’re right ahead of us.”

But though they hunted as well as they were able to in the fast-gathering darkness, there was no trace of the intruders.  They had to give up, and Tom, after going to the boathouse to see that the arrow was all right, returned to the house, where he told the engineer and housekeeper what had brought him back and how he had surprised the two men.

“Is everything all right, Garret?” he concluded.  “Dad is nervous and frightened.  I must telephone him at the hotel to-night and let him know, for I promised to come back.  I can’t, though, until to-morrow.”

“Everything is all right as far as I know,” answered Jackson.  “I’ve kept a careful watch and the burglar alarm has been in working order.  Mrs. Baggert and I haven’t been disturbed a single night since you went away.  It’s curious that the men should be here the very night you come back.  Maybe they followed you.”