"Listen to that!" exclaimed Pete, in consternation.
"Somebody's comin'!" gasped Harper. "If we don't make a run out of this we'll be nabbed."
Whipple jumped to a gas bracket against one of the rough board walls. It was not an ordinary bracket, but had a wide mouth to which a piece of hose could be attached. This had been used by the police officials to replenish the gas in the silk envelope of the Hawk.
With one jerk of his hand Whipple turned the gas full on.
"Get out!" he called to the two with him.
Pete and Harper tumbled through the door into the shed. Whipple hurried after them but paused a moment on the threshold to give a wild, taunting laugh.
"That's what Brady told us ter do," said he, savagely, "an' we've done it. Git clear o' this, if ye can!"
With that, Whipple slammed the door.
The fate to which the murderous scoundrel had consigned the two boys was a fearful one. Even as the door closed, Matt could smell the odor of gas pouring into the small room and poisoning the air.