"I wonder if he was some ordinary tramp, looking for what he could steal, or if he was one of the gang after dad's invention?" thought Tom as he sprinted ahead.
By this time the youth was clear of the group of buildings and in sight of a tall, board fence, which surrounded the Swift estate on three sides. Here and there, along the barrier, were piled old packing-cases, so that it would be easy for a fugitive to leap upon one of them and so get over the fence. Tom thought of this possibility in a moment.
"I guess he got over ahead of me," the lad exclaimed, and he peered sharply about. "I'll catch him on the other side!"
At that instant Tom tripped over a plank and went down full length, making quite a racket. When he picked himself up he was surprised to see the man he was after dart from inside a big box and start for the fence, near a point where there were some packing-cases piled up, making a good approach to the barrier. The fugitive had been hiding, waiting for a chance to escape, and Tom's fall had alarmed him.
"Here! Hold on there! Come back!" cried the youth as he recovered his wind and leaped forward.
But the man did not stay. With a bound he was up on the pile of boxes, and the next moment he was poised on top of the fence. Before leaping down on the other side, a jump at which even a practiced athlete might well hesitate, the fleeing stranger paused and looked back. Tom gazed at him and recognized the man in an instant. He was the third of the mysterious trio whom the lad had seen in the Mansburg restaurant.
"Wait a minute! What do you want sneaking around here?" shouted Tom as he ran forward. The man returned no answer, and an instant later disappeared from view on the other side of the fence.
"He jumped down!" thought Tom. "A big leap, too. Well, I've got to follow. This is a queer proceeding. First one, then the second, and now the third of those men seem determined to get something here. I wonder if this one succeeded? I'll soon find out."
The lad was up on the pile of packing-cases and over the fence in almost record time. He caught a glimpse of the fugitive running toward the woods. Then the boy leaped down, jarring himself considerably, and took after the man.
But though Tom was a good runner he was handicapped by the fact that the man had a start of him, and also by the fact that the stranger had had a chance to rest while hiding for the second time in the big box, while Tom had kept on running. So it is no great cause for wonder that Mr. Swift's son found himself being distanced.