“If I only knew what was going on in there,” thought Tom.  “Maybe, after all, the men haven’t got the model and papers here.  Yet, if they haven’t, why are they staying in the old house?  I must get a look in and see what’s going on.  Lucky there are no shades to the windows.  I wish it would get dark.”

It seemed that the sun would never go down and give place to dusk, but finally Tom, crouching in his hiding place, saw the shadows grow longer and longer, and finally the twilight of the woods gave place to a density that was hard to penetrate.  Tom waited some time to see if the guard kept up the circuit, but with the approach of night the man seemed to have gone into the house.  Tom saw a light gleam out from the lonely mansion.  It came from a window on the ground floor.

“There’s my chance!” exclaimed the lad, and, crawling from his hiding place, he advanced cautiously toward it.

Tom went forward only a few feet at a time, pausing almost every other step to listen.  He heard no sounds, and was reassured.  Nearer and nearer he came to the old house.  The gleam of the light fell upon his face, and fearful that some one might be looking from the window, he shifted his course, so as to come up from one side.  Slowly, very slowly he advanced, until he was right under the window.  Then he found that it was too high up to admit of his looking in.  He felt about until he had a stone to stand on.

Softly he drew himself up inch by inch.  He could hear the murmur of voices in the room.  Now the top of his head was on a level with the sill.  A few more inches and his eyes could take in the room and the occupants.  He was scarcely breathing.  Up, up he raised himself until he could look into the apartment, and the sight which met his eyes nearly caused him to lose his hold and topple backward.  For grouped around a table in a big room were the three men whom he had seen in the automobile.  But what attracted his attention more than the sight of the men was an object on the table.  It was the stolen model!  The men were inspecting it, and operating it, as he could see.  One of the trio had a bundle of papers in his hand, and Tom was sure they were the ones stolen from him.  But there could be no doubt about the model of the turbine motor.  There it was in plain sight.  He had tracked the thieves to their hiding place.

Then, as he watched, Tom saw one of the men produce from under the table a box, into which the model was placed.  The papers were next put in, and a cover was nailed on.  Then the men appeared to consult among themselves.

By their gestures Tom concluded that they were debating where to hide the box.  One man pointed toward the lake, and another toward the forest.  Tom was edging himself up farther, in order to see better, and, if possible, catch their words, when his foot slipped, and he made a slight noise.  Instantly the men turned toward the window, but Tom had stooped down out of sight, just in time.