He sat down under a bush and ate some of the lunch he had brought, sipping water from a bottle he had in his bundle. Then, after a half hour, he looked again. The gun was still pointed out of the window, seeming to be aimed at whoever should advance directly against the mill.

“Still there,” mused Tom angrily. “They are taking no chances.” Intently from his screened post of observation, he watched the gun barrel. Then a strange thought came to him—a thought that sent the blood tingling through him.

“Of course!” he cried to himself. “Why didn’t I think of it before? Now to see if I’m right.”

Boldly he stood up, in plain view of anyone from the window. The gun did not move to follow his action. It remained pointing in the same direction.

“That’s it!” he exulted. “The gun is just fixed there! No one is holding it. It’s just like the trick once played in some battle. It’s a dummy gun. Hurray! I’m all right now. They have gone out, and left the gun pointing from the window to scare anyone who might come along.”

Still Tom did not abandon all caution. He realized that though those guarding his chums might be gone from the top story, they still might be somewhere in the mill.

“I’ve got to be careful,” our hero assured himself. “But I’ll take a few chances.”

Approaching until he stood close under the open window from which the gun protruded, he tossed a stone up. It fell within the casement, and Tom heard it drop on the floor.

“That ought to raise something,” he said, looking warily around to see if he was observed. There was no movement, and no one appeared.